@article{MAN_1963__151_161082, author = {R. CARROLL}, title = {Problems in {Linked} {Operators.} {I.}}, journal = {Mathematische Annalen}, pages = {272--282}, publisher = {mathdoc}, volume = {151}, year = {1963}, zbl = {0123.31103}, url = {http://geodesic.mathdoc.fr/item/MAN_1963__151_161082/} }