Crisostomo, I. T. (2002). The president as salesperson and manager. Manila Bulletin.
Chicago-viite (17. p.)Crisostomo, Isabelo T. "The President as Salesperson and Manager." Manila Bulletin 2002.
MLA-viite (9. p.)Crisostomo, Isabelo T. "The President as Salesperson and Manager." Manila Bulletin, 2002.
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