NomismaNomisma was the ancient Greek word for money or coin.
In the Byzantine empire, it the denomination of gold coin. In the late tenth century the nomisma, was split into
two separate denominations, a heavier histamenon and a lighter
tetarteron. From 1092 onward, the heavier coin was called a
hyperpyron, while the lighter coin ceased to be struck. Source: Grierson, Philip. Byzantine Coins. (London, 1999).

Nomisma - Untersuchung auf dem Gebiete der Antiken MünzkundeH. von Fritze & H. Gaebler. Nomisma-Untersuchung auf dem Gebiete der Antiken Münzkunde. (Berlin, 1907-1923).Coinage - Investigations in the field of ancient numismatics.
Reprints available. A most important series of ground breaking monographs on ancient Greek coins.Most useful content includes:Gaebler, H. “Die Silberprägung von Lampsakos” in Nomisma XII (1923). Von Fritze, H. “Die Elektronprägung von Kyzikus” in Nomisma VII (1912). Von Fritze, H. “Die Silberprägung von Kyzikus” in Nomisma IX (1914). Von Fritze, H. “Die autonome Kupferprägung von Kyzikus” in Nomisma X (1917). Von Fritze, H. “Die autonomen Münzen von Ainos” in Nomisma IV (1909).

PDF with volumes I-XII: https://archive.org/details/bub_gb_IPM1AQAAMAAJ

NomismaNomisma was the ancient Greek word for money or coin.
In the Byzantine empire, it the denomination of gold coin. In the late tenth century the nomisma, was split into
two separate denominations, a heavier histamenon and a lighter
tetarteron. From 1092 onward, the heavier coin was called a
hyperpyron, while the lighter coin ceased to be struck. Source: Grierson, Philip. Byzantine Coins. (London, 1999).

Nomisma - Untersuchung auf dem Gebiete der Antiken MünzkundeH. von Fritze & H. Gaebler. Nomisma-Untersuchung auf dem Gebiete der Antiken Münzkunde. (Berlin, 1907-1923).Coinage - Investigations in the field of ancient numismatics.
Reprints available. A most important series of ground breaking monographs on ancient Greek coins.Most useful content includes:Gaebler, H. “Die Silberprägung von Lampsakos” in Nomisma XII (1923). Von Fritze, H. “Die Elektronprägung von Kyzikus” in Nomisma VII (1912). Von Fritze, H. “Die Silberprägung von Kyzikus” in Nomisma IX (1914). Von Fritze, H. “Die autonome Kupferprägung von Kyzikus” in Nomisma X (1917). Von Fritze, H. “Die autonomen Münzen von Ainos” in Nomisma IV (1909).

PDF with Nomisma volumes I-XII: https://archive.org/details/bub_gb_IPM1AQAAMAAJ