Dyfyniad APA
Holtz, R. D., Kovacs, W. D., & Sheahan,Thomas C. (2013). An introduction to geotechnical engineering (2nd ed.). Pearson Education.
Dyfyniad Arddull Chicago
Holtz, Robert D., William D. Kovacs, and Sheahan,Thomas C. An Introduction to Geotechnical Engineering. 2nd ed. Noida: Pearson Education, 2013.
Dyfyniad MLA
Holtz, Robert D., et al. An Introduction to Geotechnical Engineering. 2nd ed. Pearson Education, 2013.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.