1. Ánh, P. N., An Embedding Theorem for Abelian Categories J. Algebra 167 (1994), 627–633.
2. Ánh, P. N., Wiegandt, R., Morita Duality for Grothendieck Categories, J. Algebra 168 (1994), 273–293.
3. Hannák, L., Linearly Compact Algebras, Annales Univ. Sci. Budapest. 21 (1978), 129–137.
4. Johnstone, P. T., Topos Theory, Academic Press, 1977.
5. Leavitt, W. G., A Minimally Ernbeddable Ring, Periodica Math. Hun-gar. 12 (1981), 129–140.