Sari Wahyuni, author
Penerbit Salemba Empat, 2011
Buku Teks
edited by James Flood, Shirley Brice Heath, and Diane Lapp
MacMillan Library Reference USA, 1996
Buku Referensi
Pink, Sarah, author
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Buku Teks
Ackoff, Russell Lincoln, 1919-, author
John Wiley & Sons, 1962
Buku Teks
Palys, T.S. (Theodore Stephen), author
Nelson Education, 2014
Buku Teks