Frontier Society
Martinus Njhoff, 1971
Buku Teks
Frontier Society
Martinus Njhoff, 1971
Buku Teks
Dobson, Rosemary
Over the frontier
Angus & Robertson, 1978
Buku Teks SO
Capra, Fritjof
The hidden connections
Harper Collins, 2002
Buku Teks
Packard, Vance
The hidden persuaders
Penguin, 1960
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