@article{MZ_1985__190_173607,
     author = {Paul Gauduchon and Andrew Balas},
     title = {Any {Hermitian} {Metric} of {Constant} {Non-Positive} {(Hermitian)} {Holomorphic} {Sectional} {Curvature} on a {Compact} {Complex} {Surface} is {K\"ahler.}},
     journal = {Mathematische Zeitschrift},
     pages = {39--44},
     publisher = {mathdoc},
     volume = {190},
     year = {1985},
     zbl = {0549.53063},
     url = {http://geodesic.mathdoc.fr/item/MZ_1985__190_173607/}
}