--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/CITATION	Sun Mar 03 02:34:44 2013 +0000
@@ -0,0 +1,20 @@
+To cite GNU Octave in publications use:
+
+  John W. Eaton, David Bateman, and Søren Hauberg (2009).  GNU Octave version
+  3.0.1 manual: a high-level interactive language for numerical computations.
+  CreateSpace Independent Publishing Platform.  ISBN 1441413006,
+  URL http://www.gnu.org/software/octave/doc/interpreter/
+
+A BibTeX entry for LaTeX users is:
+
+  @book{,
+    author    = {John W. Eaton and David Bateman and S\oren Hauberg},
+    title     = {{GNU Octave} version 3.0.1 manual: a high-level interactive language for numerical computations},
+    publisher = {CreateSpace Independent Publishing Platform},
+    year      = {2009},
+    note      = {{ISBN} 1441413006},
+    url       = {http://www.gnu.org/software/octave/doc/interpreter},
+  }
+
+We have invested a lot of time and effort in creating GNU Octave, please cite it
+when using it.  See also `citation pkgname' for citing Octave packages.

--- a/Makefile.am	Sat Mar 02 19:31:26 2013 -0500
+++ b/Makefile.am	Sun Mar 03 02:34:44 2013 +0000
@@ -37,6 +37,7 @@
   INSTALL.OCTAVE \
   NEWS \
   README \
+  CITATION \
   bootstrap \
   bootstrap.conf \
   build-aux/find-files-with-tests.sh \
@@ -132,7 +133,9 @@
 	mv $@.t $@
 .PHONY: ChangeLog
 
-octetc_DATA = NEWS
+octetc_DATA = \
+  NEWS \
+  CITATION
 
 DIRS_TO_MAKE = \
   $(localfcnfiledir) \

--- a/NEWS	Sat Mar 02 19:31:26 2013 -0500
+++ b/NEWS	Sun Mar 03 02:34:44 2013 +0000
@@ -177,6 +177,9 @@
       CC_VERSION  (now GCC_VERSION)
       CXX_VERSION (now GXX_VERSION)
 
+ ** A citation command has been added to display information on how to
+    cite Octave and packages in publications.  The package system will
+    look for and install CITATION files from packages.
 
 Summary of important user-visible changes for version 3.6:
 ---------------------------------------------------------

--- a/bootstrap.conf	Sat Mar 02 19:31:26 2013 -0500
+++ b/bootstrap.conf	Sun Mar 03 02:34:44 2013 +0000
@@ -156,7 +156,7 @@
   ## with building the rest of Octave, and INSTALL, which is linked from
   ## gnulib/doc/INSTALL by the bootstrap script.
 
-  for f in NEWS README COPYING; do
+  for f in NEWS README COPYING CITATION; do
     if ! test -f $f; then
       echo "required file $f is missing" 2>&1
       exit 1

--- a/doc/interpreter/package.txi	Sat Mar 02 19:31:26 2013 -0500
+++ b/doc/interpreter/package.txi	Sun Mar 03 02:34:44 2013 +0000
@@ -182,6 +182,11 @@
 following files:
 
 @table @code
+@item package/CITATION
+This is am optional file describing instructions on how to cite
+the package for publication.  It will be displayed verbatim by the
+function @code{citation}.
+
 @item package/COPYING
 This is a required file containing the license of the package.  No
 restrictions is made on the license in general.  If however the

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/scripts/miscellaneous/citation.m	Sun Mar 03 02:34:44 2013 +0000
@@ -0,0 +1,51 @@
+## Copyright (C) 2013 Carnë Draug
+##
+## This file is part of Octave.
+##
+## Octave is free software; you can redistribute it and/or modify it
+## under the terms of the GNU General Public License as published by
+## the Free Software Foundation; either version 3 of the License, or (at
+## your option) any later version.
+##
+## Octave is distributed in the hope that it will be useful, but
+## WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+## General Public License for more details.
+##
+## You should have received a copy of the GNU General Public License
+## along with Octave; see the file COPYING.  If not, see
+## <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn  {Command} {} citation
+## @deftypefnx {Command} {} citation @var{package}
+## Display instructions to cite GNU Octave and packages in publications.
+##
+## When called without an argument, displays information on how to cite the core
+## GNU Octave system in publications.  When given a package name @var{package},
+## display information on to cite it.  However, note that some packages may not
+## have instructions on how to cite them.
+##
+## The GNU Octave developers and its active community of package authors have
+## invested a lot of time and effort in creating GNU Octave as it is today.
+## Please give credit where credit is due and cite GNU Octave and its packages
+## when you use them.
+##
+## @end deftypefn
+
+## Author: Carnë Draug <carandraug+dev@gmail.com>
+## Idea and documentation from R's citation() (also under GPL)
+
+function citation (package = "octave")
+
+  if (nargin > 1)
+    print_usage ();
+  else
+    display_info_file ("citation", package, "CITATION");
+  endif
+
+endfunction
+
+%!error citation (1, 2)
+%!error <citation: PACKAGE must be a string> citation (1)
+%!error <citation: package .* is not installed> citation ("__NOT_A_VALID_PKG_NAME__")

--- a/scripts/miscellaneous/module.mk	Sat Mar 02 19:31:26 2013 -0500
+++ b/scripts/miscellaneous/module.mk	Sun Mar 03 02:34:44 2013 +0000
@@ -1,6 +1,7 @@
 FCN_FILE_DIRS += miscellaneous
 
 miscellaneous_PRIVATE_FCN_FILES = \
+  miscellaneous/private/display_info_file.m \
   miscellaneous/private/__xzip__.m
 
 miscellaneous_FCN_FILES = \
@@ -10,6 +11,7 @@
   miscellaneous/bunzip2.m \
   miscellaneous/bzip2.m \
   miscellaneous/cast.m \
+  miscellaneous/citation.m \
   miscellaneous/comma.m \
   miscellaneous/compare_versions.m \
   miscellaneous/computer.m \

--- a/scripts/miscellaneous/news.m	Sat Mar 02 19:31:26 2013 -0500
+++ b/scripts/miscellaneous/news.m	Sun Mar 03 02:34:44 2013 +0000
@@ -17,8 +17,8 @@
 ## <http://www.gnu.org/licenses/>.
 
 ## -*- texinfo -*-
-## @deftypefn  {Function File} {} news
-## @deftypefnx {Function File} {} news (@var{package})
+## @deftypefn  {Command} {} news
+## @deftypefnx {Command} {} news @var{package}
 ## Display the current NEWS file for Octave or an installed package.
 ##
 ## When called without an argument, display the NEWS file for Octave.
@@ -30,42 +30,13 @@
 
   if (nargin > 1)
     print_usage ();
-  elseif (! ischar (package))
-    error ("news: PACKAGE must be a string");
+  else
+    display_info_file ("news", package, "NEWS");
   endif
 
-  if (strcmpi (package, "octave"))
-    octetcdir = octave_config_info ("octetcdir");
-    newsfile  = fullfile (octetcdir, "NEWS");
-  else
-    installed = pkg ("list");
-    names     = cellfun (@(x) x.name, installed, "UniformOutput", false);
-    ## we are nice and let the user use any case on the package name
-    pos = strcmpi (names, package);
-    if (!any (pos))
-      error ("Package '%s' is not installed.", package);
-    endif
-    newsfile = fullfile (installed{pos}.dir, "packinfo", "NEWS");
-  endif
-
-  if (! exist (newsfile, "file"))
-    if (strcmpi (package, "octave"))
-      error ("news: unable to locate NEWS file");
-    else
-      error ("news: unable to locate NEWS file for package %s", package);
-    endif
-  endif
-
-  fid = fopen (newsfile, "r");
-  while (ischar (line = fgets (fid)))
-    puts (line);
-  endwhile
-  fclose (fid);
-
 endfunction
 
 
 %!error news (1, 2)
-%!error <PACKAGE must be a string> news (1)
-%!error <Package .* is not installed> news ("__NOT_A_VALID_PKG_NAME__")
-
+%!error <news: PACKAGE must be a string> news (1)
+%!error <news: package .* is not installed> news ("__NOT_A_VALID_PKG_NAME__")

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/scripts/miscellaneous/private/display_info_file.m	Sun Mar 03 02:34:44 2013 +0000
@@ -0,0 +1,59 @@
+## Copyright (C) 2013 Carnë Draug
+##
+## This file is part of Octave.
+##
+## Octave is free software; you can redistribute it and/or modify it
+## under the terms of the GNU General Public License as published by
+## the Free Software Foundation; either version 3 of the License, or (at
+## your option) any later version.
+##
+## Octave is distributed in the hope that it will be useful, but
+## WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+## General Public License for more details.
+##
+## You should have received a copy of the GNU General Public License
+## along with Octave; see the file COPYING.  If not, see
+## <http://www.gnu.org/licenses/>.
+
+## news() and citation() are very much alike. They both do the same thing, just
+## for different files. This function does all the work.
+
+function display_info_file (func, package, file)
+
+  if (nargin != 3)
+    print_usage ();
+  endif
+
+  if (! ischar (package))
+    error ("%s: PACKAGE must be a string", func);
+  endif
+
+  if (strcmpi (package, "octave"))
+    octetcdir = octave_config_info ("octetcdir");
+    filepath  = fullfile (octetcdir, file);
+  else
+    installed = pkg ("list");
+    names     = cellfun (@(x) x.name, installed, "UniformOutput", false);
+    pos       = strcmpi (names, package);
+    if (! any (pos))
+      error ("%s: package '%s' is not installed.", func, package);
+    endif
+    filepath = fullfile (installed{pos}.dir, "packinfo", file);
+  endif
+
+  if (! exist (filepath, "file"))
+    if (strcmpi (package, "octave"))
+      error ("%s: broken installation -- unable to locate %s file", func, file);
+    else
+      error ("%s: unable to locate %s file for package %s", func, file, package);
+    endif
+  endif
+
+  fid = fopen (filepath, "r");
+  while (ischar (line = fgets (fid)))
+    puts (line);
+  endwhile
+  fclose (fid);
+
+endfunction

--- a/scripts/pkg/private/copy_files.m	Sat Mar 02 19:31:26 2013 -0500
+++ b/scripts/pkg/private/copy_files.m	Sun Mar 03 02:34:44 2013 +0000
@@ -105,6 +105,7 @@
   packinfo_copy_file ("DESCRIPTION", "required", packdir, packinfo, desc, octfiledir);
   packinfo_copy_file ("COPYING", "required", packdir, packinfo, desc, octfiledir);
 
+  packinfo_copy_file ("CITATION", "optional", packdir, packinfo, desc, octfiledir);
   packinfo_copy_file ("NEWS", "optional", packdir, packinfo, desc, octfiledir);
   packinfo_copy_file ("ONEWS", "optional", packdir, packinfo, desc, octfiledir);
   packinfo_copy_file ("ChangeLog", "optional", packdir, packinfo, desc, octfiledir);