The book i have mentions them but doesn't talk about their behavior. I have cichild atlas vol 2 and tetra dwarf cichild.Originally described by Kullander in 1980. Every book since then discusses the species.
Ok thanks so moderately aggressive to same species member. When i checked CA 1 wasn't available - my hope is he revises it and reprint it in the not forever future.CA 1 (if you can find it) has a very detailed discussion of A. gephyra. CA2 primarily discusses species not in CA1. Linke & Staeck's Tetra book is not as detailed but adequate in care and maintenance. Anyway, behavior-wise think of A. gephyra behaving like A. agassizii.