AG Book (or AG Buch) is a derivative of Akzidenz-Grotesk that brings it closer to Helvetica. Made for the Diatronic when Berthold couldn’t obtain a license for the original Helvetica. [SchumacherGebler]
Originally made in light, regular, regular italic, medium, medium italic (1969), light italic, ultra light, ultra light italic, bold, light condensed, condensed, medium condensed, bold condensed, light extended, extended, medium extended, bold extended (1972), and light condensed italic (1973) styles. [Berthold 1980] Later expanded with several outlined, rounded and outlined rounded (1980) styles and a Stencil (1985). The digital versions span even more styles.