Villaviray, J. (2002). PPA based on capital investment says Viray. Manila Times.
Cita Chicago (17th ed.)Villaviray, Johnna. "PPA Based on Capital Investment Says Viray." Manila Times 2002.
Cita MLA (9th ed.)Villaviray, Johnna. "PPA Based on Capital Investment Says Viray." Manila Times, 2002.
Atenció: Aquestes cites poden no estar 100% correctes.