hard to get to

A Good Man Is Hard to Find

Expensive and hard to visit doctors

Hard Data

hard to

hard to come by

hard to deal with

hard to defeat

hard to handle

Hard to leach gold ore

hard to machine material

Hard to machine materials

Hard to mine orebody

hard to pronounce

hard-to-bleach pulp

hard-to-bleach pulps

hard-to-cut material

Hard-to-cut materials

hard-to-degrade pulping effluent