Tobin, Allan J
Asking about life
Thomson, Brooks/Cole, 2005
 Buku Teks SO
Tobin, Allan J.
Biology now for Tobin/Dusheck : asking about life
Brooks/Cole, Thomson, 2005
 Multimedia
Barnard, Chris
Asking questions in biology : a guide to hypothesis-testing, experimental design and presentation in practical work and research projects
Pearson Prentice Hall, 2007
 Buku Teks
Keosian, John
Origin of life
Reinhold Publishing Corporation, 1964
 Buku Teks
Postlethwait, John H.
Explore life
Brooks/Cole, Thomson Learning, 2003
 Buku Teks SO