Planetary Nebulae: Proceedings of the 180th Symposium of the International Astronomical Union, Held in Groningen, The Netherlands, August, 26–30, 1996

Instabilities in Luminous Early Type Stars: Proceedings of a Workshop in Honour of Professor Cees De Jager on the Occasion of his 65th Birthday held in Lunteren, The Netherlands, 21–24 April 1986