1998, INTEGRAL EQUATIONS AND OPERATOR THEORY, Karlovich,AY
1998, MATHEMATICAL NOTES, Karlovich,AY
1998, SEMIGROUP FORUM, Fernandes,VH
1998, LINEAR ALGEBRA AND ITS APPLICATIONS, daSilva,JAD;Fernandes,R;Fonseca,A
1998, ORDER-A JOURNAL ON THE THEORY OF ORDERED SETS AND ITS APPLICATIONS, Blyth,TS;Silva,HJ