Marfil, M. (1999). Erap names old DOST hand science secretary. Philippine Daily Inquirer.
Lua i Stíl Chicago (17ú heag.)Marfil, Martin. "Erap Names Old DOST Hand Science Secretary." Philippine Daily Inquirer 1999.
Lua MLA (9ú heag.)Marfil, Martin. "Erap Names Old DOST Hand Science Secretary." Philippine Daily Inquirer, 1999.
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