Almeida J. Equations for pseudovarieties. In: Formal properties of finite automata and applications (Ramatuelle, 1988). Vol 386. Springer, Berlin; 1989. 1. p. 148-164p. (Lecture Notes in Comput. Sci.; vol 386).Edit

Almeida J, Azevedo A. The join of the pseudovarieties of $\scr R$-trivial and $\scr L$-trivial monoids. J. Pure Appl. Algebra. 1989;60:129-137.Edit

Almeida J. On power varieties of semigroups. J. Algebra. 1989;120:1-17.Edit

Almeida J. Residually finite congruences and quasi-regular subsets in uniform algebras. Portugal. Math.. 1989;46:313-328.Edit

Almeida J. Semidirect products of pseudovarieties from the universal algebraist's point of view. J. Pure Appl. Algebra. 1989;60:113-128.Edit

Yakubovich SB. A constructive method for constructing integral convolutions. Dokl. Akad. Nauk BSSR. 1990;34:588-591, 666.

Almeida J. An elementary proof that finite groups are projectively torsion-free. Portugal. Math.. 1990;47:437-444.Edit

Almeida J. The equation $\bf PX=\bf PJ$. In: Proceedings of the International Symposium on the Semigroup Theory and its Related Fields (Kyoto, 1990). Shimane Univ., Matsue; 1990. 1. p. 1-11p. Edit

Basto-Gonçalves J. Local controllability in $3$-manifolds. Systems Control Lett.. 1990;14:45-49.

Almeida J. On pseudovarieties, varieties of languages, filters of congruences, pseudoidentities and related topics. Algebra Universalis. 1990;27:333-350.Edit

Almeida J. Semidirectly closed pseudovarieties of locally trivial semigroups. Semigroup Forum. 1990;40:315-323.Edit

Bokowski J, de Oliveira AG. Simplicial convex $4$-polytopes do not have the isotopy property. Portugal. Math.. 1990;47:309-318.Edit

Kha\u\i NT, Yakubovich SB. Some two-dimensional integral transformations of convolution type. Dokl. Akad. Nauk BSSR. 1990;34:396-398, 474.Edit

Bokowski J, de Oliveira AG, Richter-Gebert J. Algebraic varieties characterizing matroids and oriented matroids. Adv. Math.. 1991;87:160-185.Edit

Labouriau L., Labouriau IS. The Arrhenius plot of a physiological rate process is never linear. Ciência e Cultura. 1991;43(5):363-369.Edit

Almeida J. On direct product decompositions of finite $\scr J$-trivial semigroups. Internat. J. Algebra Comput.. 1991;1:329-337.Edit

Almeida J. On finite simple semigroups. Proc. Edinburgh Math. Soc. (2). 1991;34:205-215.Edit

Yakubovich SB, Luchko Y.. The generalizations of integral analog of the Leibniz rule on the $G$-convolutions. Extracta Math.. 1991;6:119-122.Edit

Yakubovich SB, Luchko Y.. Generalizations of the Leibniz rule to integral convolutions. Dokl. Akad. Nauk BSSR. 1991;35:111-115, 188.Edit

Luchko Y., Yakubovich SB. Generating operators and convolutions for some integral transformation. Dokl. Akad. Nauk BSSR. 1991;35:773-776, 860.Edit

Basto-Gonçalves J. Geometric conditions for local controllability. J. Differential Equations. 1991;89:388-395.

Almeida J. Implicit operations on finite $\scr J$-trivial semigroups and a conjecture of I. Simon. J. Pure Appl. Algebra. 1991;69:205-218.Edit

Yakubovich SB, Kha\u\i NT. Integral convolutions for $H$-transformations. Izv. Vyssh. Uchebn. Zaved. Mat.. 1991:72-79.Edit

Yakubovich SB. Integral convolutions of Laplace type for $G$-transforms. Vests\=ı Akad. Navuk BSSR Ser. F\=ız.-Mat. Navuk. 1991:11-16, 123.

Almeida J. On iterated semidirect products of finite semilattices. J. Algebra. 1991;142:239-254.Edit