@article{ZNSL_2001_280_a10,
     author = {D. V. Ivanov},
     title = {Absence of three-dimensional totally geodesic submanifolds in the manifold of directions of physical space},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {173--174},
     publisher = {mathdoc},
     volume = {280},
     year = {2001},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_2001_280_a10/}
}