@article{GDZPPN002100959,
title = {The d-invariant of compact nilmanifolds.},
journal = {Inventiones mathematicae},
volume = {75},
year = {1984},
pages = {113-116},
zbl = {0558.55009},
url = {http://dml.mathdoc.fr/item/GDZPPN002100959}
}
Singhof, W. The d-invariant of compact nilmanifolds.. Inventiones mathematicae, Tome 75 (1984) pp. 113-116. http://gdmltest.u-ga.fr/item/GDZPPN002100959/