Sydenham, E. The Coinage of the Roman Republic. (London, 1952).
(1) Extremely common
(2) Very common
(3) Common
(4) Scarce
(5) Very scarce
(6) Rare
(7) Very rare
(8) Extremely rare
(9) Exceedingly rare
(10) Of the greatest rarity
Also See:
Sydenham Caesarea
Sydenham Aes Grave