@article{MS2_1985__57_166945,
     author = {D.N. Holtzman},
     title = {Pyramids of higher order cohomology operations in the p-torsion-free category.},
     journal = {Mathematica Scandinavica},
     pages = {127--154},
     publisher = {mathdoc},
     volume = {57},
     year = {1985},
     zbl = {0562.55018},
     url = {http://geodesic.mathdoc.fr/item/MS2_1985__57_166945/}
}