Soil Conservation on the Downs Seminar, Toowoomba, Queensland, & Agricultural Technologists of Australasia. (1977). Soil Conservation on the Downs Seminar, Toowoomba D.D.I.A.E., 12 August 1977. Agricultural Technologists of Australasia.

Soil Conservation on the Downs Seminar, Toowoomba, Queensland, and Agricultural Technologists of Australasia. Soil Conservation on the Downs Seminar, Toowoomba D.D.I.A.E., 12 August 1977. Toowoomba, Q.: Agricultural Technologists of Australasia, 1977.

Soil Conservation on the Downs Seminar, Toowoomba, Queensland, and Agricultural Technologists of Australasia. Soil Conservation on the Downs Seminar, Toowoomba D.D.I.A.E., 12 August 1977. Agricultural Technologists of Australasia, 1977.