Beyond the Zone System by Phil Davis (1998) 4th edition.

Also includes these extras.

BTZS Video Workshop (2 hours) - Now on DVD with workbook

This two hour DVD video covers the important points of the Beyond The Zone System method. When you are done, you’ll be able to characterize paper, film and have a firm understanding on what effects are really gained with one film or developer over another. The video is invaluable to both the beginner and the advanced practitioner. A workbook is included to help you track the lessons and provide further information on the methodology.

BTZS Lite (a collection of PDFs written by Phil Davis highlighting metering concepts)

Armed with BTZS Lite and either Expo/Dev or the PowerDial photographers can get good exposures - the first time - without film testing. BTZS Lite consists of a CD-ROM (Mac or PC readable) with five Adobe Acrobat* files written by Phil that explain metering using either a spotmeter or an incident meter and calculating the correct exposure using the BTZS PowerDial or the Expo/Dev software. Using actual photographs Phil explains meter placement and other techniques to handle difficult exposure situations. Topics covered include Zone System Metering with Expo/Dev, Visualization with the Incident Meter, Film/Developer Gradation Effects, Using the BTZS Expo/Dev Program, Using the BTZS PowerDial and much more.

BTZS PowerDial

The BTZS Power Dial is a inexpensive but sophisticated device that can help you determine film exposure and development for many popular films under most subject conditions. This novel dial slide rule is constructed of durable laminated card stock to withstand day-to-day use in the field, and is convenient to carry and simple to use