1. Catalog of the firm F. Klaus (Federal German Republic) (1973).
2. Pump with Ceramic Magnet Drive, Mach. Prod. Eng.,126, No. 3258, 467 (1975).
3. US Patent No. 3762839, cl. FO4635/04 (1973).
4. V. Krouz, Centrifugal and Related Pumps, ChSAN, Prague (1956).
5. Japanese Patent No. 48-9401, cl. (63)3 B5 (FO4d) (1973).