Claire is seen reading Rick Romer's Vision of Astrology in the episodes "Confidence Man" and "Left Behind".
The book in the episode "Confidence Man"
This book seems to be a meta-fictional book prop, created for use in the Lost universe. It is established early in the series that Claire is strongly interested in astrology. The book's author is the name of both the travel agent in "Walkabout" and a former set decorator, Rick Romer. Romer's last episode as set decorator on Lost was "Exposé", the episode previous to when the book appeared on the show.