APA

(1973). Positive approaches to drop prevention. Washington: for sale by the Supt. of Docs., U.S. Govt, Print. Off.

Chicago

1973. Positive approaches to drop prevention. Washington: for sale by the Supt. of Docs., U.S. Govt, Print. Off.

Harvard

(1973). Positive approaches to drop prevention. Washington: for sale by the Supt. of Docs., U.S. Govt, Print. Off.

MLA

Positive approaches to drop prevention. Washington: for sale by the Supt. of Docs., U.S. Govt, Print. Off. 1973.