Columbia subject headings:
Graubner, Gotthard, 1930-2013.
Mack, Heinz, 1931-
Opałka, Roman.
Piene, Otto, 1928-2014.
Uecker, Günther, 1930-
Zero (Group of artists)
Harvard subject headings:
Artists--Interviews.
Princeton subject headings:
Graubner, Gotthard, 1930-2013.
Mack, Heinz, 1931-
Opałka, Roman.
Piene, Otto, 1928-2014.
Uecker, Günther, 1930-
Zero (Group of artists)