Vila-Vilaró, B., Robinson, A., & Wagner, S. (1992). The extended narrowline region of NGC4151: Spatial variations of the emission line ratios and their implications. Physics of active galactic nuclei.
Chicago Style (17th ed.) CitationVila-Vilaró, Baltasar, Andrew Robinson, and Stefan Wagner. "The Extended Narrowline Region of NGC4151: Spatial Variations of the Emission Line Ratios and Their Implications." Physics of Active Galactic Nuclei 1992.
MLA (9th ed.) CitationVila-Vilaró, Baltasar, et al. "The Extended Narrowline Region of NGC4151: Spatial Variations of the Emission Line Ratios and Their Implications." Physics of Active Galactic Nuclei, 1992.
Warning: These citations may not always be 100% accurate.