1. Duvall, T. L. Jr Nature 300, 242–243 (1982).
2. Gough, D. O. Mem. Soc. astr. Italiana 55, 13–35; in Solar Physics and Interplanetary Travelling Phenomena (eds Chen, B. & de Jager, C.) (Yunnan Observatory, Kunming, 1984).
3. Duvall, T. L. Jr. & Harvey, J. W. Nature 302, 24–27 (1983).
4. Harvey, J. W. & Duvall, T. L. Jr Proc. Conf. solar Seismol. Space (eds Ulrich, R. K. et al.) 165–172 (Jet Propulsion Laboratory Publication 84-84, Pasadena, 1984).
5. Christensen-Dalsgaard, J. & Gough, D. O. Bull. Am. astr. Soc. 13, 859–860 (1981).