Nakagawa, K., Yamada, K., Tsurue, T., Takeda, S., Ishizaki, K., Quilao, T., . . . Vinluan, F. Characterization of coal ash. Philippine Engineering Journal.
Chicago Style aipamenaNakagawa, K., et al. "Characterization of Coal Ash." Philippine Engineering Journal .
MLA aipamenaNakagawa, K., et al. "Characterization of Coal Ash." Philippine Engineering Journal, .
Kontuz: berrikusi erreferentzia hauek erabili aurretik.