Exhibition catalogue published in conjunction with shows held at Museum Folkwang Essen, Germany, June 15 - July 29, 1979; and at Rijksmuseum Kröller - Müller, Otterlo, Netherlands, August 18 - October 7, 1979. Texts by Zdenek Felix and Ellen Joosten. Includes artist statements, biography, and bibliography. Profusely illustrated in color and black-and-white. Text in German, Dutch, and English.