Ohrtman, Franklin D.
Softswitch : architecture for VoIP / Franklin D. Ohrtman
McGraw-Hill, 2003
 Buku Teks
Patrick, John
History of the American Nation
Macmillan Publishing Company, 1984
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Lower, Arthur R.M.
Colony to nation: a history of Canada
Longmans, Green, 1959
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Scott, Ernest
A short history of Australia / by Ernest Scott
Oxford University Press, 1916
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Scott, Ernest
A short history of Australia / Ernest Scott
Oxford University Press, 1920
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