Soft rock or light rockAlan Stephenson, David Reese, Mary Beadle, 2013, Broadcast Announcing Worktext: A Media Performance Guide p. 198.

A design method for drilled piers in soft rock
Groundwater potential modelling in a soft rock area using a GIS.
Dynamic Deformation Characteristics of Sedimentary Soft Rock
Fracture testing of a soft rock with semi-circular specimens under three-point bending. I: Mode I
Fracture testing of a soft rock with semi-circular specimens under three-point bending. II: Mixed-mode
Fracture testing of a soft rock with semi-circular specimens under three-point bending. Part 1—mode I
Fracture testing of a soft rock with semi-circular specimens under three-point bending. Part 1—Mode 1
Displacement analysis of tunnel support in soft rock around a shallow highway tunnel at Golovec
A predictive Mesoscale model of the erosion and profile development of soft rock shores
Numerical Simulation Research on Coupling Support Theory of Roadway With in Soft Rock at Depth