APA (7th ed.) Citation

Perko, H. A. (2009). Helical piles: A practical guide to design and installation. John Wiley & Sons.

Chicago Style (17th ed.) Citation

Perko, Howard A. Helical Piles: A Practical Guide to Design and Installation. Hoboken, NJ: John Wiley & Sons, 2009.

MLA (8th ed.) Citation

Perko, Howard A. Helical Piles: A Practical Guide to Design and Installation. John Wiley & Sons, 2009.

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