APA

STRAHLER A. N., . (1977). Principles of Physical Geology. New York: Harper & Row.

Chicago

STRAHLER Arthur Newell, . 1977. Principles of Physical Geology. New York: Harper & Row.

Harvard

STRAHLER A. N., . (1977). Principles of Physical Geology. New York: Harper & Row.

MLA

STRAHLER Arthur Newell, . Principles of Physical Geology. New York: Harper & Row. 1977.