References to Semiparametric Normalisation of riverine substance loads
Stålnacke P, Grimvall, A., Sundblad, K., and Wilander, A.: 1999,
'Trends in nitrogen transport in Swedish rivers', Environ. Monit. Assess. 59, 47-72.

Stålnacke, P., and Grimvall, A.: 2001,
'Semiparametric approaches to flow-normalisation and source apportionment of substance transport in rivers', Environmetrics 12, 233-250.