@article{GDZPPN002298872, title = {An Extension of Sch\"utte's Klammersymbols.}, journal = {Mathematische Annalen}, volume = {174}, year = {1967}, pages = {203-216}, zbl = {0162.01901}, url = {http://dml.mathdoc.fr/item/GDZPPN002298872} }
GERBER, H. An Extension of Schütte's Klammersymbols.. Mathematische Annalen, Tome 174 (1967) pp. 203-216. http://gdmltest.u-ga.fr/item/GDZPPN002298872/