Alan Walker, Liam Foster, editors
Elgar Research Colection, 2014
Buku Teks
Moen, Phyllis, author
Oxford University Press, 2016
eBooks
Ferrini, Rebecca, author
McGraw-Hill, 2013
Buku Teks
McGraw-Hill, [date of publication not identified]
Buku Teks
Lia Juniarni, author
2013
UI - Tesis (Membership)