Nilpotent groups of class two that can appear as central quotient groups
Rendiconti del Seminario Matematico della Università di Padova, Tome 84 (1990) , pp. 241-248. 
@article{RSMUP_1990__84__241_0,
     author = {Heineken, Hermann},
     title = {Nilpotent groups of class two that can appear as central quotient groups},
     journal = {Rendiconti del Seminario Matematico della Universit\`a di Padova},
     pages = {241--248},
     publisher = {Seminario Matematico of the University of Padua},
     volume = {84},
     year = {1990},
     zbl = {0722.20011},
     mrnumber = {1101296},
     language = {en},
     url = {archive.numdam.org/item/RSMUP_1990__84__241_0/}
}
Heineken, Hermann. Nilpotent groups of class two that can appear as central quotient groups. Rendiconti del Seminario Matematico della Università di Padova, Tome 84 (1990) , pp. 241-248. http://archive.numdam.org/item/RSMUP_1990__84__241_0/

[1] F.R. Beyl - J. TAPPE, Extensions, representations, and the Schur multiplicator, Lecture Notes in Mathematics, 958, Berlin, Heidelberg, New York, 1989. | Zbl 0544.20001

[2] R. Scharlau, Paare alternierender Formen, Math. Z., 147 (1976), pp. 13-19. | MR 419484 | Zbl 0304.15008

[3] A.L. Wishnevetskii, Groups of class 2 and exponent p with commutator subgroups of order p2, Doklady Akad. Nauk Ukrain. S.S.R. Ser. A, 103, 9 (1980), pp. 9-11 (Russian). | Zbl 0594.20013