Psychics
   Christian site argues that psychics rely on "familiar spirits," which are devils.
   http://www.teachingpages.co.uk/minilesson/psychics.html

Skeptic's Dictionary: Biorhythms
   Overview and analysis.
   http://www.skepdic.com/biorhyth.html

Trust the Bible
   Lists Bible verses claiming that evil spirits are active in astrology, fortune-telling, mediums, and the occult.
   http://www.trustbible.com/astrology.htm