APA

National Stone Association N., . (1993). Stone sand seminar at Knoxville, TN, March 28-30, 1993. Proceedings. Washington DC: National Stone Association, NSA.

Chicago

National Stone Association NSA, . 1993. Stone sand seminar at Knoxville, TN, March 28-30, 1993. Proceedings. Washington DC: National Stone Association, NSA.

Harvard

National Stone Association N., . (1993). Stone sand seminar at Knoxville, TN, March 28-30, 1993. Proceedings. Washington DC: National Stone Association, NSA.

MLA

National Stone Association NSA, . Stone sand seminar at Knoxville, TN, March 28-30, 1993. Proceedings. Washington DC: National Stone Association, NSA. 1993.