APA (7th ed.) Citation

willoughby, d. A. (2005). horizontal directional drilling. The McGraw-Hill Companies,Inc.

Chicago Style (17th ed.) Citation

willoughby, david A. Horizontal Directional Drilling. The McGraw-Hill Companies,Inc, 2005.

MLA (8th ed.) Citation

willoughby, david A. Horizontal Directional Drilling. The McGraw-Hill Companies,Inc, 2005.

Warning: These citations may not always be 100% accurate.