GameFAQs: Circle of the Moon - Includes walkthroughs, FAQs, maps, lists, secrets, codes, user reviews, and message board. - http://www.gamefaqs.com/portable/gbadvance/data/449471.html
GameSpy - Reviewed by Andrew S. Bub. Includes screen shots. Score: 82 out of 100. - http://archive.gamespy.com/reviews/september01/castlevania/
GameSpot - Reviewed by Jeff Gerstmann. Includes screen shots, reader ratings, cheat codes, glitches, and gameplay movies. Score: 9.6 out of 10. - http://www.gamespot.com/gba/adventure/castlevaniacircleofthemoon/
eLook - Contains a summary of cheats. - http://www.elook.org/games/cheats/gba/244.shtml
AllRPG.com: Castlevania: Circle of the Moon - Includes screenshots, artwork, coverage, a preview, and a review for this Game Boy Advance RPG. - http://www.allrpg.com/games/castlevaniacircleofthemoon/