Grey, H. M. (1927). The land of to morrow: A mule back trek through the swamps and forest of eastern Bolivia (1a. ed.). H. F. & G. Witherby.
Cita Chicago (17th ed.)Grey, Henry M. The Land of to Morrow: A Mule Back Trek Through the Swamps and Forest of Eastern Bolivia. 1a. ed. Londres: H. F. & G. Witherby, 1927.
Cita MLA (9th ed.)Grey, Henry M. The Land of to Morrow: A Mule Back Trek Through the Swamps and Forest of Eastern Bolivia. 1a. ed. H. F. & G. Witherby, 1927.
Atenció: Aquestes cites poden no estar 100% correctes.