Hattatt

Hattatt, Richard. A Visual catalogue of Richard Hattatt 's Ancient Brooches. (Oxbow Books, Oxford, 2000).

In English. The only commonly available English language book on fibulae. Good for basic identification and rough dating only.

Also see:
Hattatt ABOA
Hattatt ARBB
Hattatt BOA
Hattatt IARB