Saks, A., Velner, H.-A. Economically viable and environment-friendly hydro energy in Estonia // "Environmental Impact and Water Management in a Catchment Area Perspective" : 24-26 September, 2001, Tallinn, Estonia : proceedings of the Symposium dedicated to the 40th Anniversary of Institute of Environmental Engineering at Tallinn Technical University. Tallinn : Tallinn Technical University, 2001. p. 160-164.