Schefler, W. C. (1976). Biology: Principles and issues. Addison - Wesley.
Cita Chicago Style (17a ed.)Schefler, William C. Biology: Principles and Issues. Reading Mass: Addison - Wesley, 1976.
Cita MLA (9a ed.)Schefler, William C. Biology: Principles and Issues. Addison - Wesley, 1976.
Precaución: Estas citas no son 100% exactas.