Flat World Knowledge is good.

Flat World Knowledge is open source education.
“We preserve the best of the old — books by leading experts, peer‑reviewed and developed to high editorial standards, fully supported by review copies, teaching supplements and great service. Then we change everything.”
that is all ~ check em out.
http://www.flatworldknowledge.com/

Mu Merge

For the record I don’t think that ms is a good file prefix.