[1] R. Davis: 
Quasicotripleable categories. Proc. A. M. S. 35 (1972), 43-48. 
MR 0316531[2] R. Davis: 
Universal coalgebra and categories of transition systems. Math. Syst. Theory 4 (1970), 91-95. 
MR 0268243 | 
Zbl 0191.01203[3] K. Drbohlav: On coalgebras. Summer session on the theory of ordered sets and general algebra, Cikháj 1969, University of J. E. Purkyně, Brno, 81-87.
[4] K. Drbohlav: 
On quasicovarieties. Acta F. R. N. Univ. Comen. Math., mimoriadne číslo, 1971, 17-20. 
MR 0382119 | 
Zbl 0232.08003[6] I. Kopeček: 
Distinguishing subsets in general algebras. Časopis pro pěstování matematiky, 106 (1981), 94-100. 
MR 0613712[7] F. E. J. Linton: Is the dual of a coalgebra category an algebra category?. Multigraph, Dalhousie Univ., 1970.
[8] E. G. Manes: 
Algebrcic theories. Graduate texts in math. 26, Springer-Verlag, New York-Heidelberg-Berlin, 1976. 
MR 0419557[9] J. Rosický: 
Codensity and binding categories. Comment. Math. Univ. Carolinae, 16 (1975), 515-529. 
MR 0376800[10] J. Rosický: On algebraic categories. Proc. Colloq. Univ. Alg., Esztergom 1977.
[11] J. Słominski: 
On the greatest congruence relation contained in an equivalence relation and its applications to the algebraic theory of machines. Coll. Math. 24 (1974), 31-43. 
MR 0356978[12] A. Tarski: 
Zur Grundlegung der Booleschen Algebra I. Fund. Math. 24 (1935), 177-198. 
Zbl 0011.00203