TOP CHOICES
(The Major Play Publishing Catalogues; they each have a one-act play categories)

1. SAMUEL FRENCH, INC.

2. DRAMATISTS PLAY SERVICE

3. BROADWAY PLAY PUBLISHING CO.

4. DRAMATIC PUBLISHING

OTHER PLACES TO CHECK:

1. THE DRAMATIC EXCHANGE (actually has scripts available on-line to peruse).

2. HANSEN DRAMA BOOKSTORE

3. ACT I BOOKSTORE

4. AMAZON.COM

5. THE INTERNET BOOKSHOP