1. and , Cone Penetration Testing, Blackie Academic & Professional, 1997, pp. 1-7, 172-190, 218-222.
2. ‘Pore pressure sounding instrument’. Proc. ASCE, Spec. Conf. on In situ Measurement of Soil Properties, Vol. II, Raleigh, N.C., 1975, pp. 48-54.
3. and , ‘The piezometer probe’. Proc. ASCE Spec. Conf. on In situ Measurement of Soil Properties, Raleigh, N.C., 1975, pp. 536-545.
4. and , ‘A penetrometer for simultaneous measurement of cone resistance, sleeve friction and dynamic pore pressure’. Proc. ESOPT II, Amsterdam, Vol. 2, 1982, pp. 963-970.