1. “De k-waarde van vliegas” (the k-value of fly ash);Selst van;Intron-report 89252,1989
2. “Spreiding van de k-waarde van vliegas in beton” (variance of the k-value of fly ash in concrete);Cornelissen;KEMA-report 91776-CBP 90-112,1990
3. Strenth aand durability of concree with coal fly ash as an additive;Wesche;Betonwerk + Fertigteiltechnik,1984
4. The reaction of fly ash in concrete, a critical examination;Fraaij;Cement and concrete research,1989
5. “Verlaging minimum cementgehalte bij gebruik van poederkoolvliegas” (reduction of minimum cement content if fly ash is applied);Selst van;Intron report 90402,1990