You all know that Google.com is the most popular search engine in the world.
So, I present to you some tips that will help you to find ebooks with Googlge.
First you need to find Apache's (default) Index page
and try this query -
+("index of") +("/ebooks"|"/book") +(chm|pdf|zip|rar) +apache
If you want to find a particular ebook file
then try this query -
allinurl: +(rar|chm|zip|pdf|tgz) TheTitle of the book
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