Background/Reference
Peter Miller's original paper: [http://miller.emu.id.au/pmiller/books/rmch/ Recursive Make Considered Harmful]
Emile van Bergen's article: [http://www.xs4all.nl/~evbergen/nonrecursive-make.html Implementing non-recursive make]
Paul Smith's article: [http://make.paulandlesley.org/multi-arch.html Multi-Architecture Builds Using GNU make]