@article{ASNSP_1938_2_7_2_157_0,
     author = {Michal, Aristotle D. and Hyers, Donald H.},
     title = {Theory and applications of abstract normal coordinates in a general differential geometry},
     journal = {Annali della Scuola Normale Superiore di Pisa - Scienze Fisiche e Matematiche},
     pages = {157--175},
     publisher = {Scuola normale superiore},
     volume = {Ser. 2, 7},
     number = {2},
     year = {1938},
     zbl = {0018.36701},
     language = {en},
     url = {http://www.numdam.org/item/ASNSP_1938_2_7_2_157_0/}
}