Berger, Melvin. Enzymes in action. - New York Crowell [1971] - 151 p. illus. 21 cm. Bibliography: p. 143-145. ISBN: 0690267355 LCCN: 76132291 Subjects--Topical Terms: Enzymes--Juvenile literature. LC Class. No.: QP601 / .B393 1971 Dewey Class. No.: 660/.63