@article{1259943863,
author = {HIROSE, Ken},
title = {An investigation on degrees of unsolvability},
journal = {J. Math. Soc. Japan},
volume = {20},
number = {4},
year = {1968},
pages = { 609-633},
language = {en},
url = {http://dml.mathdoc.fr/item/1259943863}
}
HIROSE, Ken. An investigation on degrees of unsolvability. J. Math. Soc. Japan, Tome 20 (1968) no. 4, pp. 609-633. http://gdmltest.u-ga.fr/item/1259943863/