@article{CMH_1961__35_139207,
     author = {Kentaro Yano and Tadashi Nagano},
     title = {On {Geodesic} {Vector} {Fields} in a {Compact} {Orientable} {RIEMANNian} {Space.}},
     journal = {Commentarii mathematici Helvetici},
     pages = {55--64},
     publisher = {mathdoc},
     volume = {35},
     year = {1961},
     zbl = {0100.35904},
     url = {http://geodesic.mathdoc.fr/item/CMH_1961__35_139207/}
}