@article{GDZPPN002232316, title = {On free constructions.}, journal = {Manuscripta mathematica}, volume = {70}, year = {1991}, pages = {335-374}, zbl = {0739.51005}, url = {http://dml.mathdoc.fr/item/GDZPPN002232316} }
Strambach, Karl; Funk, Martin. On free constructions.. Manuscripta mathematica, Tome 70 (1991) pp. 335-374. http://gdmltest.u-ga.fr/item/GDZPPN002232316/