@article{JRAM_1985__361_152753,
     author = {W. Singhof and Ch. Deninger},
     title = {On the d-invariant of compact solvmanifolds.},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {47--49},
     year = {1985},
     volume = {361},
     zbl = {0569.22006},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1985__361_152753/}
}