Grätzer George A.; Lakser Harry; Quackenbush Robert W.: Congruence-preserving extensions of congruence-finite lattices to isoform lattices. In: Acta scientiarum mathematicarum, (75) 1-2. pp. 13-28. (2009)
Grätzer George A.; Quackenbush Robert W.; Schmidt Elégius Tamás: Congruence-preserving extensions of finite lattices to isoform lattices. In: Acta scientiarum mathematicarum, (70) 3-4. pp. 473-494. (2004)
Grätzer George A.; Lakser Harry; Quackenbush Robert W.: On the lattice of quasivarieties of distributive lattices with pseudocomplementation. In: Acta scientiarum mathematicarum, (42) 3-4. pp. 257-263. (1980)