APA (7th ed.) Citation

Heidt, J., Wagner, S., & Erkens, U. (1997). Optical and UV observations of the BL Lacertae object PKS 2155-304. Astronomy and astrophysics, 325, .

Chicago Style (17th ed.) Citation

Heidt, Jochen, Stefan Wagner, and Ulrike Erkens. "Optical and UV Observations of the BL Lacertae Object PKS 2155-304." Astronomy and Astrophysics 325 (1997).

MLA (9th ed.) Citation

Heidt, Jochen, et al. "Optical and UV Observations of the BL Lacertae Object PKS 2155-304." Astronomy and Astrophysics, vol. 325, 1997.