@article{10_4064_cm_34_2_241_243,
     author = {John W. Rutter},
     title = {A classification of secondary cohomology operations},
     journal = {Colloquium Mathematicum},
     pages = {241--243},
     publisher = {mathdoc},
     volume = {34},
     number = {2},
     year = {1975},
     doi = {10.4064/cm-34-2-241-243},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm-34-2-241-243/}
}