@article{TRSPY_1975_135_a23,
     author = {J. E. Roberts},
     title = {Must there be a~gauge group?},
     journal = {Informatics and Automation},
     pages = {206--209},
     publisher = {mathdoc},
     volume = {135},
     year = {1975},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/TRSPY_1975_135_a23/}
}