MLA

Boughton Cobb, Elizabeth Farnsworth, and Cheryl Lowe. A Field Guide to Ferns and Their Related Families: Northeastern and Central North America. 2nd ed. Boston: Houghton Mifflin, 2005.

APA

Boughton Cobb, B. Cobb, Elizabeth Farnsworth, E. Farnsworth, & Cheryl Lowe, C. Lowe. (2005). A Field Guide to Ferns and their Related Families: Northeastern and Central North America. 2nd ed. Boston: Houghton Mifflin.

Chicago

Boughton Cobb, Elizabeth Farnsworth, and Cheryl Lowe. A Field Guide to Ferns and Their Related Families: Northeastern and Central North America. : 2nd ed. Boston: Houghton Mifflin, 2005.