Billstein, R., Libeskind, S., & Lott, J. W. (1990). A problem solving approach to mathematics for elementary school teachers (4th ed.). Benjamin/Cummings.
Chicago-referens (17:e uppl.)Billstein, Rick, Shlomo Libeskind, och Johnny W. Lott. A Problem Solving Approach to Mathematics for Elementary School Teachers. 4th ed. Redwood City, Calif: Benjamin/Cummings, 1990.
MLA-referens (9:e uppl.)Billstein, Rick, et al. A Problem Solving Approach to Mathematics for Elementary School Teachers. 4th ed. Benjamin/Cummings, 1990.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.