1. Brueckner, G. E., 1981, in Solar Active Regions, Skylab Solar Workshop III, ed. F. Q. Orrall, (Colorado Assoc. Univ. Press) 113
2. Brueckner, G. E., & Bartoe, J.-D. F., 1983, ApJ, 272, 329
3. Buchholz B., & Ulmschneider P., 1994, in Cool Stars, Stellar Systems and the Sun, ed. J. P. Caillault, ASP Conf. Series 64, 363
4. Buchholz, B., Ulmschneider, P., & Cuntz M., 1998, ApJ, 494, 700
5. Buchsbaum, G., 1987, Diplom thesis, Univ. Würzburg, Germany