APA

Barton R., . (1955). How to watch birds. New York: McGraw-Hill.

Chicago

Barton Roger, . 1955. How to watch birds. New York: McGraw-Hill.

Harvard

Barton R., . (1955). How to watch birds. New York: McGraw-Hill.

MLA

Barton Roger, . How to watch birds. New York: McGraw-Hill. 1955.