APA (7th ed.) Citation

Wielen, R., Schwan, H., Dettbarn, C., Jahreiß, H., & Lenhardt, H. (1999). The combination of HIPPARCOS data with ground-based astrometric measurements. Modern astrometry and astrodynamics.

Chicago Style (17th ed.) Citation

Wielen, Roland, Heiner Schwan, Christian Dettbarn, Hartmut Jahreiß, and Helmut Lenhardt. "The Combination of HIPPARCOS Data with Ground-based Astrometric Measurements." Modern Astrometry and Astrodynamics 1999.

MLA (9th ed.) Citation

Wielen, Roland, et al. "The Combination of HIPPARCOS Data with Ground-based Astrometric Measurements." Modern Astrometry and Astrodynamics, 1999.