To add on to this, every search engine is generally pretty bad at math related searches. It may be something worth looking into.
1. Poor interpretation: "distribution of compact support" brings up nothing very useful in DDG -- a bunch of linkfarms, it looks like -- but in Google the third result for me is a relevant .pdf from Oregon State.
2. Users attempting to ad-hoc convert math notation into ascii: Google understands "l 2 space", but DDG thinks I mean "l2space" which is some sort of gallery in I don't know where.
It's a hard, nontrivial problem.