May, Rollo. Paulus : Tillich as spiritual teacher / Rollo May. - Revised. - Dallas, Tex. : Saybrook Publishing Co., Inc., c1988. - 124 p. ; 21 cm. - Mind age series . Includes bibliographical references. ISBN: 0933071183 (pbk.) Subjects--Personal Names: Tillich, Paul, 1886-1965. Subjects--Topical Terms: Tillich, Paul, 1886-1965.