Pilatowicz, Grazyna, author
John Wiley & Sons, 1994
Buku Referensi
Serrats, Marta, author
Page one publishing pte ltd, 2011
Buku Referensi
Mega Parlintara Kusmirat, author
2018
UI - Skripsi (Membership)
Massachusetts: Rockport Publishers,, 1997
Buku Teks
Plunkett, Drew, author
Laurence King, 2010
Buku Teks