The Oxford handbook of contextual political analysis
edited by Robert E. Goodin, Charles Tilly
Oxford University Press, 2008
 Buku Referensi
Denscombe, Martyn
Research proposals: a practical guide
Open University Press, 2012
 Buku Teks
Sommer, Robert
A practical guide to behavioral research: tools and techniques
Oxford University Press, 2001
 Buku Teks SO
Morris, Richard
Dismantling the universe : the nature of scientific discovery
Simon and Schuster, 1983
 Buku Referensi
Popper, Karl R.
The logic of scientific discovery
Basic Books, 1959
 Buku Teks SO