Metra International & Sauti Consulting Engineers. Philippine transport survey: National transport development.
Cita Chicago (17th ed.)Metra International i Sauti Consulting Engineers. Philippine Transport Survey: National Transport Development.
Cita MLA (9th ed.)Metra International i Sauti Consulting Engineers. Philippine Transport Survey: National Transport Development.
Atenció: Aquestes cites poden no estar 100% correctes.