Oracle Certification Study Guides:

http://www.thaifast.com/Sun/appd2_cg.pdf

http://www.thaifast.com/Sun/appd6_cg.pdf

http://www.thaifast.com/Sun/dba8_cg.pdf

http://www.thaifast.com/Sun/dba8i_cg.pdf

http://www.thaifast.com/Sun/dbo8_cg.pdf

http://www.thaifast.com/Sun/dbo8i_cg.pdf

http://www.thaifast.com/Sun/java_cg.pdf

Amit Ray.