APA (7th ed.) Citation

Helsel, D. R., & Hirsch, R. M. (2002). Statistical methods in water resources / D.R. Helsel and R.M. Hirsch. USGS.

Chicago Style (17th ed.) Citation

Helsel, Dennis R., and Robert M. Hirsch. Statistical Methods in Water Resources / D.R. Helsel and R.M. Hirsch. [S.l.]: USGS, 2002.

MLA (9th ed.) Citation

Helsel, Dennis R., and Robert M. Hirsch. Statistical Methods in Water Resources / D.R. Helsel and R.M. Hirsch. USGS, 2002.

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