APA (7e ed.) Bronvermelding

BETTGER FRANK. (1982). HOW I RAISED MYSELF FROM FAILURE TO SUCCESS IN SELLING. SIMON & SCHUSTER INC.

Chicago (17e ed.) Bronvermelding

BETTGER FRANK. HOW I RAISED MYSELF FROM FAILURE TO SUCCESS IN SELLING. NEW YORK: SIMON & SCHUSTER INC, 1982.

MLA (9e ed.) Bronvermelding

BETTGER FRANK. HOW I RAISED MYSELF FROM FAILURE TO SUCCESS IN SELLING. SIMON & SCHUSTER INC, 1982.