Drooyan, Irving
Elementary algebra : structure and skills
John Wiley & Sons, 1981
Buku Teks
Hearing, Sylvia, 1954-
Computerized accounting : an integrated skills approach / Sylvia Hearing
Regents/Prentice Hall, 1994
Buku Teks
Alexander, L.G.
Developing skills : an integrated course for intermediate students
Longman, 1964
Buku Teks
Heinemann, Margot
The adventurers /Margot Heinemann
Seven Seas, 1962
Buku Teks
Heinemann atlas 2
Heinemann Educational Books, 1986
Buku Referensi