1. Reduction of skin- friction between soil and metal wall by the electro-osmosis method;Asakawa;Tras. of Japan Soc. Civil Engrs.,1959
2. Reduction of negative skin friction on steel piles to rock;Bjerrum;Proc. 7th Int. Conf. Soil Mech. Found. Eng.,1969
3. Failure of pile-supported structures caused by settlements;Broms;Proc. 6 th European Conf. Soil Mech. Found. Eng.,1976
4. Reducing negative friction with bitumen slip layers;Claessen;J. Geotech. Eng. Div., ASCE,1974
5. Effect d’ accrochage et méthode d’ évaluation du frottement négatif;Combarieu,1974