APA (7th ed.) Citation

Douglas, N., & Bohlke, D. (2015). Reading explorer (2nd ed.). National Geographic Learning.

Chicago Style (17th ed.) Citation

Douglas, Nancy, and David Bohlke. Reading Explorer. 2nd ed. Boston, Massachusetts: National Geographic Learning, 2015.

MLA (9th ed.) Citation

Douglas, Nancy, and David Bohlke. Reading Explorer. 2nd ed. National Geographic Learning, 2015.