APA
Robert D. Holtz K., . (1981). An Introduction to Geotechnical Engineering. New Jersey: Prentice Hall.
Chicago
Robert D. Holtz Kovacs, . 1981. An Introduction to Geotechnical Engineering. New Jersey: Prentice Hall.
Harvard
Robert D. Holtz K., . (1981). An Introduction to Geotechnical Engineering. New Jersey: Prentice Hall.
MLA
Robert D. Holtz Kovacs, . An Introduction to Geotechnical Engineering. New Jersey: Prentice Hall. 1981.