1. Linear Operators I;Dunford,1964
2. Über die Abgrenzung der Eigenwerte einer Matrix;Gershgorin;Izv. Akad. Nauk S.S.S.R.,1931
3. Ordered Vector Spaces;Jameson,1970
4. Gerschgorin theorems for partitioned matrices;Johnston;Lin. Alg. and Appl.,1971
5. Infinite Dimensional Analogues of Gershgorin Type Estimates;Kovarik,1971