Applications, Dover. Halmos, P. R., 1960. Naive Set Theory. Van Nostrand. BjarniJónsson and Constantine Tsinakis, Relation algebras as residuated Boolean algebras
ok Heiðreks" National and University Library of Iceland的存檔,存档日期2007-05-08, Guðni Jónsson's and Bjarni Vilhjálmsson's edition at Norrøne Tekster og Kvad