Алгол (звезда) — разлика између измена

* {{Cite book|editor = Paul Murdin | year = 2001 | title = Encyclopedia of Astronomy and Astrophysics | publisher = Institure of Physics Publishing |language = {{ен}} | id = ISBN 0-7503-0440-5 | page=5065| ref = harv}}

* {{Cite book | title=Philip's Astronomy Encyclopedia | publisher=Philip's | year=2002 | isbn=0–540–07863–8 | editor=Patrick Moore| language = {{ен}} | page=427| ref = harv}}