TY - JOUR AU - S. Kawaler AU - D. Winget AU - I. Iben AU - Carl Hansen BT - The Astrophysical Journal DA - Jan-03-1986 DO - 10.1086/164013 PY - 1986 EP - 530 T2 - The Astrophysical Journal TI - Evolutionary period changes in variable helium-rich white dwarfs UR - http://articles.adsabs.harvard.edu/full/1986ApJ...302..530K VL - 302 SN - 0004-637X ER -