Casanova, S. (2002). Prepaid cards boost internet industry growth. Manila Times.
Chicago Style aipamenaCasanova, Sheryll. "Prepaid Cards Boost Internet Industry Growth." Manila Times 2002.
MLA aipamenaCasanova, Sheryll. "Prepaid Cards Boost Internet Industry Growth." Manila Times, 2002.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.