K. P. SHUM; Xu YONGHUA. Study about Crossed Product R#\(_{\sigma}\)G and a Group-Ring R[G]. Recent Advances in Mathematical Research and Computer Science Vol. 1, [S. l.], p. 92–110, 2021. DOI: 10.9734/bpi/ramrcs/v1/11625D. Disponível em: https://stm.bookpi.org/RAMRCS-V1/article/view/4341. Acesso em: 9 jun. 2026.