@article{SIGMA_2008_4_a62,
     author = {Frank B. Estabrook},
     title = {Exterior {Differential} {Systems} for {Yang{\textendash}Mills} {Theories}},
     journal = {Symmetry, integrability and geometry: methods and applications},
     year = {2008},
     volume = {4},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SIGMA_2008_4_a62/}
}