The nature of the methanol maser ring G23.657-00.127. I. The distance through trigonometric parallax measurementsv. 490EDP Sciences787-792
Bartkiewicz, A., Brunthaler, A., Szymczak, M., van Langevelde, H. J., and Reid, Mark J. 2008. "The nature of the methanol maser ring G23.657-00.127. I. The distance through trigonometric parallax measurements." Astronomy and Astrophysics, 490 787–792.