Παραπομπή APA

Walker, H. M. (1951). Mathematics essential for elementary statistics: A self teaching manual. Oxford & IBH publishing.

Παραπομπή Chicago Style

Walker, Helen M. Mathematics Essential for Elementary Statistics: A Self Teaching Manual. Calcutta: Oxford & IBH publishing, 1951.

Παραπομπή MLA

Walker, Helen M. Mathematics Essential for Elementary Statistics: A Self Teaching Manual. Oxford & IBH publishing, 1951.