Added link to Carsten Dominik's entries.db page.

README

@@ -7,7 +7,7 @@ HP48/49/50-series calculators.
 In its present state really only provides `sysrpl-mode' for editing
 SysRPL source files.  This mode implements syntax highlighting and
 documentation lookup, using data extracted from Carsten Dominik's
-``entries.db'' system RPL entries database.
+``entries.db'' system RPL entries database[1].
 
 To install rpl-tools, clone the Mercurial repository to somewhere in
 your Emac's `load-path' with
@@ -21,7 +21,7 @@ then add the following to your ~/.emacs file
 
 where the latter command activates the minor eldoc-mode in
 sysrpl-mode.  This causes a stack-effect diagram to be displayed in
-the minibuffer, corresponding to the SysRPL word under the cursor.
+the minibuffer whenever the cursor is on a SysRPL word.
 
 More info can be displayed with the `sysrpl-apropos-thing-at-point'
 command, bound to C-c C-a by default, which pops up another window
@@ -37,7 +37,15 @@ to place the current buffer into sysrpl-mode.  This can of course be
 automated by adding an appropriate rule to the 'auto-mode-alist'
 variable in your ~/.emacs file.
 
+
+REFERENCES
+==========
+
+[1] Carsten Dominik's SysRPL entries database
+    http://staff.science.uva.nl/~dominik/hpcalc/entries/index.html
+
+
 --
 Paul Onions
-24 May 2014
+25 May 2014
 paul.onions@acm.org