Trefry, David and Trefry, J. F. 1967. Kuman Language Course. Port Moresby, Papua New Guinea: Summer Institute of Linguistics.
@book{Trefry-and-Trefry-1967,
address = {Port Moresby, Papua New Guinea},
author = {Trefry, David and Trefry, J. F.},
publisher = {Summer Institute of Linguistics},
title = {Kuman Language Course},
year = {1967}
}