no. 4
On z-submonoids and z-codes
RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications, Tome 25 (1991) no. 4, pp. 305-322. 
@article{ITA_1991__25_4_305_0,
     author = {Madonia, M. and Salemi, S. and Sportelli, T.},
     title = {On $z$-submonoids and $z$-codes},
     journal = {RAIRO - Theoretical Informatics and Applications - Informatique Th\'eorique et Applications},
     pages = {305--322},
     publisher = {EDP-Sciences},
     volume = {25},
     number = {4},
     year = {1991},
     mrnumber = {1134385},
     zbl = {0764.68089},
     language = {en},
     url = {http://www.numdam.org/item/ITA_1991__25_4_305_0/}
}
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AU  - Sportelli, T.
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PY  - 1991
SP  - 305
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%A Salemi, S.
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%D 1991
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Madonia, M.; Salemi, S.; Sportelli, T. On $z$-submonoids and $z$-codes. RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications, Tome 25 (1991) no. 4, pp. 305-322. http://www.numdam.org/item/ITA_1991__25_4_305_0/

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