Stone, Ronald C.; Monet, David G. (1990). "The USNO (Flagstaff Station) CCD Transit Telescope and Star Positions Measured From Extragalactic Sources". Proceedings of IAU Symposium No. 141. 141: 369–370. Bibcode:1990IAUS..141..369S., at SAO/NASA ADS
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Stone, Ronald C.; Monet, David G. (1990). "The USNO (Flagstaff Station) CCD Transit Telescope and Star Positions Measured From Extragalactic Sources". Proceedings of IAU Symposium No. 141. 141: 369–370. Bibcode:1990IAUS..141..369S., at SAO/NASA ADS