APA

Kehl G. L., . (1939). The principles of matallographic laboratory practice. New York: McGraw-Hill.

Chicago

Kehl George L, . 1939. The principles of matallographic laboratory practice. New York: McGraw-Hill.

Harvard

Kehl G. L., . (1939). The principles of matallographic laboratory practice. New York: McGraw-Hill.

MLA

Kehl George L, . The principles of matallographic laboratory practice. New York: McGraw-Hill. 1939.