APA (7th ed.) Citation

Portela, M. C. A. S., Thanassoulis, E., & Simpson, G. (2011). Negative data in DEA: A directional distance approach applied to bank branches.

Chicago Style (17th ed.) Citation

Portela, M. C. A. S., E. Thanassoulis, and G. Simpson. Negative Data in DEA: A Directional Distance Approach Applied to Bank Branches. 2011.

MLA (8th ed.) Citation

Portela, M. C. A. S., et al. Negative Data in DEA: A Directional Distance Approach Applied to Bank Branches. 2011.