Alison J. Heppenstall, Andrew T. Crooks, Linda M. See, Michael Batty, editor
[Springer, Springer], 2012
eBooks
Dubay, Eric, author
Bumi Media, 2016
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Robert Cornraads and five outhers, author
Reader's Digest, 2015
Buku Referensi
Naylor, Thomas H., author
John Wiley & Sons, 1971
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Gorokhovski, Vikenti, author
Springer, 2012
eBooks