@article{ASNSP_1937_2_6_1_29_0,
     author = {Glenn, Oliver E.},
     title = {Theory of gravitation. {The} problem of stationary states, and the apparatus of the echo phenomenon in radiographic transmission},
     journal = {Annali della Scuola Normale Superiore di Pisa - Scienze Fisiche e Matematiche},
     pages = {29--40},
     publisher = {Scuola normale superiore},
     volume = {Ser. 2, 6},
     number = {1},
     year = {1937},
     zbl = {0015.37605},
     language = {en},
     url = {http://archive.numdam.org/item/ASNSP_1937_2_6_1_29_0/}
}