R4

Lotus Notes 4: Mastering Application Development - Jonathan MacKenzie
Lotus Notes Developer's Guide: For Users of Release 4.0 Through 4.5 - Rose Kelleher, Paul Emond, Tom Jones
Foundations of Lotus Notes 4 Application Development: Application Development - Erica Kerwien, Sally Blanning Dejean, Erica Kerwein
Lotus Notes Power Toolkit: Cutting-Edge Tools & Techniques for Programmers (Power Toolkit/Book and Cd-Rom) - Kelly Gillespie
Lotus Notes in the Enterprise - William Kreisle, Dan Schulz, Bill Kreisle, William Kriesle
Lotus Notes 4 Unleashed - Randall A. Tamura
Mastering Lotus Notes 4 - Kenyon Brown, Kyle Brown, Francois Koutchouk, Kevin Brown
PC Week Guide to Lotus Notes Release 4 - Eric Mann, Gerry Litton
Lotus Notes 4.X & Lotus Domino 4.5 - Raul Nogales
Lotus Notes 4.X - J. Plaza
LOTUS NOTES DEVELOPERS GDE - Sams