@article{701832,
     title = {$L\_2$-Kohomologie und approximationen des Laplaceoperators},
     booktitle = {Proceedings of the 12th Winter School on Abstract Analysis},
     series = {GDML\_Books},
     publisher = {Circolo Matematico di Palermo},
     address = {Palermo},
     year = {1984},
     pages = {107-120},
     mrnumber = {MR0782709},
     zbl = {0583.58003},
     url = {http://dml.mathdoc.fr/item/701832}
}

Eichhorn, Jürgen. $L_2$-Kohomologie und approximationen des Laplaceoperators, dans Proceedings of the 12th Winter School on Abstract Analysis, GDML_Books,  (1984), pp. 107-120. http://gdmltest.u-ga.fr/item/701832/