TY - JOUR AU - S. Kawaler AU - D. Winget AU - Carl Hansen AU - I. Iben BT - The Astrophysical Journal DA - Jan-07-1986 DO - 10.1086/184701 PY - 1986 EP - L41 T2 - The Astrophysical Journal TI - The helium shell game - Nonradial g-mode instabilities in hydrogen-deficient planetary nebula nuclei UR - http://articles.adsabs.harvard.edu/full/1986ApJ...306L..41K VL - 306 SN - 0004-637X ER -