Johnsgard. Sandhill and Whooping Cranes. University of Nebraska Press.
Cita Chicago (17th ed.)Johnsgard. Sandhill and Whooping Cranes. University of Nebraska Press.
Cita MLA (8th ed.)Johnsgard. Sandhill and Whooping Cranes. University of Nebraska Press.
Atenció: Aquestes cites poden no estar 100% correctes.