Adam Sampson's differential bookmarkshttps://bookmarks.offog.org/ats/differentialAdam Sampson2012-11-25T18:52:58ZNotes on Diffy Qs: Differential Equations for Engineershttps://bookmarks.offog.org/edit?url=http%3A%2F%2Fwww.jirka.org%2Fdiffyqs%2F2012-11-25T18:52:58ZAs it says. Useful reference.