Sasselov D D.
Concertino on pulsating stars. Postepy Astronomii Krakow. 1993;41 :25-28.
Caldwell J A R, Menzies J W, Banfield R M, Catchpole R M, Whitelock P A, Feast M W, Lloyd Evans T H H, Sekiguchi K, Zijlstra A, Allen D A, et al. Spectroscopic and photometric observations of supernova 1987A. VII. Days 793 to 1770. \mnras. 1993;262 :313-324.