Spigolon, S. (2001). The McGraw-Hill civil engineering PE exam depth guide: Geotechnical engineering. New York: McGraw-Hill.
Παραπομπή Chicago StyleSpigolon, S.J. The McGraw-Hill Civil Engineering PE Exam Depth Guide: Geotechnical Engineering. New York: McGraw-Hill, 2001.
Παραπομπή MLASpigolon, S.J. The McGraw-Hill Civil Engineering PE Exam Depth Guide: Geotechnical Engineering. New York: McGraw-Hill, 2001.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.