A programed course in calculus : V infinite sequences and series
by Howard W. Alexander... [et.al.]
W.A. Benjamin, 1968
 Buku Teks SO
Makkink, H.J.
An English grammar
Nijgh and Van Ditmar, 1951
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Helling, Pam
The grammar and proofreading course
[American Management Association, ], 1992
 eBooks
Langan, John, 1942-
English essentials : what every college student needs to know about grammar, punctuation, and usage
McGraw-Hill, 2013
 Buku Teks SO
Harder, Paul O.
Basic materials in music theory a programed course/Paul O. Harder
Allyn and Bacon, 1975
 Buku Teks SO