Ramalho, Margarita Benito Semirings: morphisms, ideals. (Semi-aneis: morfismos, ideais.). (Portuguese) Zbl 0359.16021 Lisboa: Universidade de Lisboa. 26 p. (1971). Page: −5 −4 −3 −2 −1 ±0 +1 +2 +3 +4 +5 Show Scanned Page Cited in 1 Document MSC: 16Y60 Semirings PDFBibTeX XML