Trisakti International Center for Service studies FE-Usakti, 2006
Majalah, Jurnal, Buletin
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Alfabeta , 2014
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Alfabeta, 2007
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Ririn Trin Ratnasari, author
Ghalia Indonesia, 2011
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Rambat Lupiyoadi, author
Salemba Empat, 2001
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