@article{GDZPPN002062003, title = {Convolution and Quasiconformal Extension}, journal = {Commentarii mathematici Helvetici}, volume = {51}, year = {1976}, pages = {99-104}, zbl = {0323.30022}, url = {http://dml.mathdoc.fr/item/GDZPPN002062003} }
Krzyz, Jan G. Convolution and Quasiconformal Extension. Commentarii mathematici Helvetici, Tome 51 (1976) pp. 99-104. http://gdmltest.u-ga.fr/item/GDZPPN002062003/