Billingsley, Patrick, author
Allyn and Bacon, 1986
Buku Teks
edited by L.F. Pau
North Holland, 1987
Buku Teks
Clewer, Ann, author
Pearson Education, 1998
Buku Teks
by Patrick Billingsley ... [et al.]
Allyn and Bacon, 1986
Buku Teks
Huntsberger, David V., author
Allyn and Bacon, 1980
Buku Teks