Okay, I'm looking for some search engines that are a bit different, a little off the beaten trail, so to speak. I, as so may others, use Google, Dogpile, Lexis Nexus, Webferret, Alexa, et. al., but I'm hoping some of ya'll have knowledge of others that perhaps focus on information sources that aren't as broadly known. These engines can include any that target specific fields or disciplines that don't appeal to the general public, but have a wealth of knowledge for someone who wants to learn a great deal about a specific subject. I'd like to thank any respondees in advance.
Oh, and I've cross-posted (of course), so I apologize if you come across this more than once.