1. E. De Witte, co-ordinator, SCOST-Salt Compatibility of Surface Treatments, EC Contract ENV4-CT98-710
2. R.P.J. van Hees, L.J.A.R. van der Klugt, J.A.G. Koek, Steenversteviging. Keuzemodel en achtergronden (Consolidation of stone like materials. Decision model and backgrounds), Foundation of Building Research (SBR), Publication no 283, Rotterdam, 1993, ISBN 90-5367-087-4
3. RILEM TC 127-MS Recommendation MS-A.1 Determination of the resistance of wallettes against sulfates and chlorides, Materials and Structures, vol. 31, Jan.–Feb. 1998, pp 2–4
4. R.P.J. van Hees, The protection of historic brick masonry with water repellents Proceedings of the 4th Course of the C.U.M. University School Monument Conservation and Environmental Protection: ‘The Fortifications in the Mediterranean Basin: Technologies for Preservation and Conservation’, Community of the Mediterranean Universities, Rhodes, Greece, May 1998
5. Hydrofoberen van windmolens;van Hees,2003