Cita APA (7th ed.)
Tryon, R. M. (1980). Ferns of Minnesota (2d ed., rev.). University of Minnesota Press.
Cita Chicago (17th ed.)
Tryon, Rolla Milton. Ferns of Minnesota. 2d ed., rev. Minneapolis: University of Minnesota Press, 1980.
Cita MLA (9th ed.)
Tryon, Rolla Milton. Ferns of Minnesota. 2d ed., rev. University of Minnesota Press, 1980.
Atenció: Aquestes cites poden no estar 100% correctes.