VLBI for Gravity Probe B. V. Proper Motion and Parallax of the Guide Star, IM PegasiDOI: info:10.1088/0067-0049/201/1/5v. 2015
Ratner, M. I., Bartel, N., Bietenholz, M. F., Lebach, D. E., Lestrade, J. -F, Ransom, R. R., and Shapiro, Irwin. 2012. "VLBI for Gravity Probe B. V. Proper Motion and Parallax of the Guide Star, IM Pegasi." The Astrophysical Journal Supplement Series, 201 5. https://doi.org/10.1088/0067-0049/201/1/5.