APA

Robertson J. G., . (1908). A history of German literature. New York: G. P. Putnam's Sons.

Chicago

Robertson John George, . 1908. A history of German literature. New York: G. P. Putnam's Sons.

Harvard

Robertson J. G., . (1908). A history of German literature. New York: G. P. Putnam's Sons.

MLA

Robertson John George, . A history of German literature. New York: G. P. Putnam's Sons. 1908.