@article{SIGMA_2018_14_a121,
     author = {Adolfo Guillot},
     title = {Quadratic {Differential} {Equations} in {Three} {Variables} without {Multivalued} {Solutions:} {Part~I}},
     journal = {Symmetry, integrability and geometry: methods and applications},
     year = {2018},
     volume = {14},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SIGMA_2018_14_a121/}
}