APA
Price D., . (1990). International Association of Engineering Geology, IAEG. 6th international congress, Amsterdam, August 6-10, 1990. Proceedings. Vol 1-4 + symposia. Rotterdam: Balkema.
Chicago
Price DG, . 1990. International Association of Engineering Geology, IAEG. 6th international congress, Amsterdam, August 6-10, 1990. Proceedings. Vol 1-4 + symposia. Rotterdam: Balkema.
Harvard
Price D., . (1990). International Association of Engineering Geology, IAEG. 6th international congress, Amsterdam, August 6-10, 1990. Proceedings. Vol 1-4 + symposia. Rotterdam: Balkema.
MLA
Price DG, . International Association of Engineering Geology, IAEG. 6th international congress, Amsterdam, August 6-10, 1990. Proceedings. Vol 1-4 + symposia. Rotterdam: Balkema. 1990.