personally I have downloaded all the pdf documentation files into 1
folder and then I can perform a search in the whole folder (with
Acrobat Reader, but others do it, too) which delivers a list of all
results.
this is often more efficient than going through an internet search.
I think the quickest way to search the lilypond stuff is to use the
info files. The tty program to read info files is `info', or if you
like a lynx-like, colourful interface, `pinfo'. Both programs can
search for regular expressions, so looking for
two.*side
would give you a result quickly.
Of course, the Emacs info file reader can do the same; if you are not
on a Unix like platform, this is probably the solution to go.