Dragoni, Walter, Nicoletta Prosperini, and Giuseppe Vinti. 2008. “Some Observations on the Procedures for the Determination of the Liquid Limit: An Application on Plio-Pleistocenic Clayey Soils from Umbria Region (italy)”. Italian Journal of Engineering Geology and Environment, October, 185-97. https://doi.org/10.4408/IJEGE.2008-01.S-12.