Vicki Smith, Patrizia Collard, Paula Nicolson, Rowan Bayne
Mc Graw-Hill, 2012
Buku Teks
Vernon, Mark, author
RajaGrafindo Persada, 2011
Buku Teks
Hayward, Susan, author
Routledge , 2006
Buku Referensi
Bernadette Casey.... (et all...)
Routledge , 2008
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Winch, Christopher, author
Routledge, 2008
Buku Teks