In case you want a copy of the out-of-print book:

Chevron Beads from the West African Trade (Volume 1), by John & Ruth Picard, there is one for sale right now -

EBay 283553714493

The book has 8 pages of color images and 8 pages of descriptions of the beads.

The Picards issued a longer chevron book after this initial one - Vol. VII, which includes Nueva Cadiz beads.