CCNP BSCI Exam Certification Guide (CCNP Self-Study, 642, 801), 4rd Edition, By Clare Gough, Published by Cisco Press, Series: Exam Certification Guide, ISBN: 1587200856, Dec 01, 2003, Copyright 2004, Pages: 936
OR
CCNP Self-Study: Building Scalable Cisco Internetworks (BSCI), By Cisco Systems, Inc, Catherine Paquet, Diane Teare, Published by Cisco Press, Series: Certification Self-Study, ISBN: 1587050846, Jan 15, 2003, Copyright 2003,Pages: 944, 1st Edition
What's the difference, and why the two different books?