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This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. |
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CUBO, A Mathematical Journal ISSN 0716-7776 (print version) - ISSN 0719-0646 (online version) Departamento de Matemática y Estadística, Universidad de La Frontera, Temuco, Chile. Email: cubo@ufrontera.cl |
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