R. Costanza

Urban ecological systems: linking terrestrial ecological, physical, and socio-economic components of metropolitan areas
Pickett, Steward T. A., Mary L. Cadenasso, Morgan Grove, C.H. Nilon, Richard V. Pouyat, Wayne C Zipperer, and R. Costanza. 2001. “Urban Ecological Systems: Linking Terrestrial Ecological, Physical, And Socio-Economic Components Of Metropolitan Areas”. Ann. Rev. Ecol. Syst. 32: 127-157.
The value of the world's ecosystem services and natural capital
Costanza, R., R. d'Arge, R. de Groot, S. Farber, M. Grasso, B. Hannon, K. E. Limburg, et al. 1997. “The Value Of The World's Ecosystem Services And Natural Capital”. Nature 387: 253-260.