Frontier Society
Martinus Njhoff, 1971
Buku Teks
Cole, John W.
The Hidden frontier
Academic Press, 1974
Buku Teks
Oceanography the last frontier
edited by Richard C. Vetter
Voice of America, 1974
Buku Teks
Kokot, Jozef
logic of the Oder-Neisse frontier
Pozman: Wydawnictwo Zachodnie, [1957]
Buku Teks
Dobson, Rosemary
Over the frontier / by Rosemary Dobson
Angus & Robertson, 1978
Buku Teks