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Published 2001
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Published 1991
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Published 2005
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Published 1991
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Published 2001
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Published 2011
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Published 2008
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Published 1994
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Published 2009
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Published 2008
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Published 2009
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by Ong, Loo Chen
Published 2005
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Published 2008
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Published 1991
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Published 2001
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Published 2001
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Published 2003
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Published 2004
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Published 1991