Burke, Eleanor J.; Perry, Richard H.J.; Brown, Simon J. (2010). «An extreme value analysis of UK drought and projections of change in the future». Journal of Hydrology388: 131. doi:10.1016/j.jhydrol.2010.04.035.
waterlog.info
CumFreq, software for cumulative frequency analysis and probability distribution fitting [1]
Oosterbaan, R.J. (1994). «Chapter 6 Frequency and Regression Analysis». En Ritzema, H.P., ed. Drainage Principles and Applications, Publication 16. Wageningen, The Netherlands: International Institute for Land Reclamation and Improvement (ILRI). pp. 175-224. ISBN90-70754-33-9.