--- a/djvu.rst	Sun Oct 24 21:51:26 2010 +0300
+++ b/djvu.rst	Sun Oct 24 22:15:04 2010 +0300
@@ -43,6 +43,8 @@
 
 ** djvulibre.
 
+For 'pdftoppm' install xpdf (both Linux and Cygwin).
+
   $ pdftoppm -mono -r 600 -aa yes $PDF $PDF
   $ for PBM in $PDF*.pbm; do  cjb2 -dpi $DPI $PBM $PBM.djvu;  rm -f $PBM;  done