Egret, D., Didelon, P., McLean, B. J., Russell, J. L., and Turon, C. 1992, Astr. Astrophys., , 258, 217
Jenkner, H., Lasker, B. M., Sturch, C. R., McLean, B. J., Shara, M. M., and Russell, J. L. 1990, Astr. J., , 99, 2081
Lasker, B. M., Sturch, C. R., McLean, B. J., Russell, J. L., Jenkner, H., and Shara, M. M. 1990, Astr. J., , 99, 2019
Russell, J. L., Lasker, B. M., McLean, B. J., Sturch, C. R., and Jenkner, H. 1990, Astr. J., , 99, 2059
Yentis et al. 1992, in ``Digitised Optical Sky Surveys'', p.67, Ed. MacGillivray & Thomson, Kluwer