APA
(1992). The bentonite industry in North America: suppliers, reserves, processing capacity and products. [s.l.]: [s.n.].
Chicago
1992. The bentonite industry in North America: suppliers, reserves, processing capacity and products. [s.l.]: [s.n.].
Harvard
(1992). The bentonite industry in North America: suppliers, reserves, processing capacity and products. [s.l.]: [s.n.].
MLA
The bentonite industry in North America: suppliers, reserves, processing capacity and products. [s.l.]: [s.n.]. 1992.