Aharonian, F. A., Akhperjanian, A. G., Andronache, M., Barrio, J. A., Bernlöhr, K., Bojahr, H., . . . Völk, H. J. (1999). Observations of Mkn 421 during 1997 and 1998 in the energy range above 500 GeV with the HEGRA stereoscopic Cherenkov telescope system. Astronomy and astrophysics, 350, .
Chicago Style (17th ed.) CitationAharonian, Felix A., et al. "Observations of Mkn 421 During 1997 and 1998 in the Energy Range Above 500 GeV with the HEGRA Stereoscopic Cherenkov Telescope System." Astronomy and Astrophysics 350 (1999).
MLA (9th ed.) CitationAharonian, Felix A., et al. "Observations of Mkn 421 During 1997 and 1998 in the Energy Range Above 500 GeV with the HEGRA Stereoscopic Cherenkov Telescope System." Astronomy and Astrophysics, vol. 350, 1999.
Warning: These citations may not always be 100% accurate.