APA (7th ed.) Citation

Silva, L. T., & Mendes, J. F. G. (2011). A new air quality index for cities.

Chicago Style (17th ed.) Citation

Silva, Lígia Torres, and José F. G. Mendes. A New Air Quality Index for Cities. 2011.

MLA (8th ed.) Citation

Silva, Lígia Torres, and José F. G. Mendes. A New Air Quality Index for Cities. 2011.