APA Style

Krensky, S., Green, N. (1991). Christopher Columbus (Step into Reading, Step 3, Grades 1-3) Paperback . New York: Harcourt School Publishers.

MLA Style

Krensky, Stephen., Green, Norman. "Christopher Columbus (Step into Reading, Step 3, Grades 1-3) Paperback". New York: Harcourt School Publishers, 1991. Printed Book.