Steffensen, A. R. (1992). College algebra: A problem-solving approach (2nd.ed.). Harper Collins.
Cita Chicago (17th ed.)Steffensen, Arnold R. College Algebra: A Problem-solving Approach. 2nd.ed. New York: Harper Collins, 1992.
Cita MLA (9th ed.)Steffensen, Arnold R. College Algebra: A Problem-solving Approach. 2nd.ed. Harper Collins, 1992.
Atenció: Aquestes cites poden no estar 100% correctes.