Gavin, Helen, author
Sage, 2019
Buku Teks
Wrightsman, Lawrence S., author
Wadsworth/Thomson Learning, 2001
Buku Teks
Grover Maurice Godwin, editor
CRC press, 2001
Buku Teks
Taylor, Sandie, author
Routledge, 2019
Buku Teks
Ainsworth, Peter B., author
Pearson Educatios, 2000
Buku Teks