no. 2
The exact sequence in the homology of groups with integral coefficients modulo q associated to two normal subgroups
Cahiers de Topologie et Géométrie Différentielle Catégoriques, Tome 32 (1991) no. 2, pp. 113-129 
@article{CTGDC_1991__32_2_113_0,
     author = {Rodr{\'\i}guez-Fern\'andez, C. and Rodeja Fern\'andez, E. G.},
     title = {The exact sequence in the homology of groups with integral coefficients modulo $q$ associated to two normal subgroups},
     journal = {Cahiers de Topologie et G\'eom\'etrie Diff\'erentielle Cat\'egoriques},
     pages = {113--129},
     year = {1991},
     publisher = {Dunod \'editeur, publi\'e avec le concours du CNRS},
     volume = {32},
     number = {2},
     mrnumber = {1142685},
     zbl = {0758.20012},
     language = {en},
     url = {https://www.numdam.org/item/CTGDC_1991__32_2_113_0/}
}
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Rodríguez-Fernández, C.; Rodeja Fernández, E. G. The exact sequence in the homology of groups with integral coefficients modulo $q$ associated to two normal subgroups. Cahiers de Topologie et Géométrie Différentielle Catégoriques, Tome 32 (1991) no. 2, pp. 113-129. https://www.numdam.org/item/CTGDC_1991__32_2_113_0/

BR. Brown, q-Perfect Groups and Universal q-Central Extensions, Publicacions Matemdtiques 34 (1990), 291-297. | Zbl | MR

B-LR. Brown & J.-L. Loday, Van Kampen theorems for diagrams of spaces, Topology 26 (3) (1987) 311-335. | Zbl | MR

B-R J. Barja & C. Rodriguez, Homology groups Hn(-,Zq) and eight-term exact sequences, Cahiers Top. et Géom. Diff. Cat. XXXI (1990), 91-120. | Zbl | MR | Numdam

C M. Campon Andion, Una Presentación del producto tensor no abeliano.

EG.J. Ellis, Non-abelian exterior products of groups and exact sequences in the homology of groups, Glasgow Math. 29 (1987), 13-19. | Zbl | MR

E-RG.J. Ellis & C. Rodríguez, An exterior product for the homology of groups with integral coefficients modulo p, Cahiers Top. et Géom. Diff. Cat. XXX-4 (1989), 339-343. | Zbl | MR | Numdam