Sokol, Daniel K.
Springer, 2012
eBooks
Davies, Charlotte Aull, author
Routledge, 1999
Buku Teks
Loughary, John W., author
McGraw-Hill, 1979
Buku Teks
california state departement of educatio, 1956
Buku Teks
edited by David Lusted
Routledge, 1991
Buku Referensi