[2] M. KATĚTOV: 
A theorem on mappings. Comment. Math. Univ. Carolinae 8 (1967), 431-433. 
MR 0229228 
[3] H. KENYON: 
Partition of a domain, Advanced problems... . Amer. Math. Monthly 71 (1964), 219. 
MR 1532554 
[4] V. KOUBEK J. REITERMAN: 
On the category of filters. Comment. Math. Univ. Carolinae 11 (1970), 19-29. 
MR 0262141 
[5] J. M. MARANDA: 
Some remarks on limits in categories. Canad. Math. Bull. 5 (1962), 133-136. 
MR 0162831 | 
Zbl 0123.01002 
[7] A. PULTR: 
On selecting of morphisms among all mappings between underlying sets ef objects in concrete categories and realisation of these. Comment. Math. Univ. Carolinae 8 (1967), 53-83. 
MR 0210764 
[8] A. PULTR: 
Limits of functors and realisations of categories. Comment. Math. Univ. Carolinae 8 (1967), 663-682. 
MR 0229689 | 
Zbl 0189.01801 
[9] V. TRNKOVÁ P. GORALČÍK: 
On products in generalized algebraic categories. Comment. Math. Univ. Carolinae 10 (1969), 49-89. 
MR 0246932 
[10] V. TRNKOVÁ: 
Some properties ef set functors. Comment. Math. Univ. Carolinae, 10 (1969), 323-352. 
MR 0252474 
[11] V. TRNKOVÁ: 
When the product-preserving functors preserve limits. Comment. Math. Univ. Carolinae 11 (1970), 365-378., 
MR 0271190 
[12] O. WYLER: 
Operational Categories. Proceedings of the Conference on Categorial Algebra, La Jolla 1965, 295-316. 
MR 0204498