ISRM suggested method for the needle penetration test
R Ulusay (External organisation)
O Aydan (External organisation)
ZA Erguler (External organisation)
DJM Ngan-Tillard (TU Delft - Civil Engineering & Geosciences)
T Seiki (External organisation)
W Verwaal (TU Delft - Civil Engineering & Geosciences)
Y Sasaki (External organisation)
A Sato (External organisation)