1. Behavior of negative skin friction on model piles in medium plasticity silt;Koerner;Highway Research Record,1972
2. Model test and analysis of negative skin friction acting on piles;Shibata;Soils Foundations,1982
3. Pile foundations — pile groups;Broms,1976
4. Frottement negatif sur les pieux;Combarieu,1985
5. Group effect in the case of downdrag;Briaud,1991