@article{GDZPPN002348640,
title = {On a Problem of J.H.C. Whitehead and a Problem of Alonzo Church.},
journal = {Mathematica Scandinavica},
volume = {18},
year = {1966},
pages = {185-192},
zbl = {0166.26503},
url = {http://dml.mathdoc.fr/item/GDZPPN002348640}
}
Boone, W.W.; Rogers, H., Jr. On a Problem of J.H.C. Whitehead and a Problem of Alonzo Church.. Mathematica Scandinavica, Tome 18 (1966) pp. 185-192. http://gdmltest.u-ga.fr/item/GDZPPN002348640/