books.google.co.ukhttp://books.google.co.uk/books/about/The_Roman_Imperial_Coinage_pt_1_Pertinax.html?id=GxUXAQAAIAAJ&utm_source=gb-gplus-shareThe Roman Imperial Coinage: pt. 1. Pertinax to Geta, by H. Mattingly and E. A. Sydenham. pt. 2. Macrinus to Pupienus, by H. Mattingly, E. A. Sydenham, and C. H. V. Sutherland. pt. 3. Gordian III-Uranius Antoninus, by H. Mattingly, E. A. Sydenham, and C. H. V. Sutherland
The Roman Imperial Coinage: pt. 1. Pertinax to Geta, by H. Mattingly and E. A. Sydenham. pt. 2. Macrinus to Pupienus, by H. Mattingly, E. A. Sydenham, and C. H. V. Sutherland. pt. 3. Gordian III-Uranius Antoninus, by H. Mattingly, E. A. Sydenham, and C. H. V. Sutherland
The Roman Imperial Coinage: pt. 1. Pertinax to Geta, by H. Mattingly and E. A. Sydenham. pt. 2. Macrinus to Pupienus, by H. Mattingly, E. A. Sydenham, and C. H. V. Sutherland. pt. 3. Gordian III-Uranius Antoninus, by H. Mattingly, E. A. Sydenham, and C. H. V. Sutherland Volume 4, Part 3 of The Roman Imperial Coinage, Harold Mattingly