APA

Beard J. T., . (1923). Mine examination, questions and answers. New York: McGraw-Hill.

Chicago

Beard James T, . 1923. Mine examination, questions and answers. New York: McGraw-Hill.

Harvard

Beard J. T., . (1923). Mine examination, questions and answers. New York: McGraw-Hill.

MLA

Beard James T, . Mine examination, questions and answers. New York: McGraw-Hill. 1923.