Dictionary of Numismatics by J. M. Folgosa is an essential reference work in the study of numismatics, compiling a wide range of terminology, biographies, historical references, mythology, slang, engravers, and coin legends.

Published by Livraria Fernando Machado in Porto, this dictionary presents a comprehensive alphabetical and thematic overview of numismatic knowledge, useful for collectors, researchers, professionals, and curious readers.

The book includes extensive entries on technical numismatic terms, historical figures, and explanations of inscriptions found on coins, making it a valuable resource for understanding the cultural and historical aspects of coinage.

The Currency of Portugal in the World – The Coinage of Brazil, by J. Ferraro Vaz, is a historical and numismatic study focusing on the circulation and influence of Portuguese currency in Brazil. The book examines the monetary systems used during the Portuguese colonial period and the historical evolution of coinage in the Brazilian territory.

Published in Braga in 1986, the work forms part of Ferraro Vaz’s broader studies on the presence of Portuguese coinage across the former Portuguese overseas world. Illustrated and accessible in style, the volume connects numismatic evidence with the history of Portuguese maritime expansion.

By linking coinage, trade, and imperial administration, the book provides useful insights into the monetary history of Portuguese Brazil and remains of interest to collectors and researchers of Luso-Brazilian numismatics.

Portugal, error coin of medal alignment XX centavos 1951 Bronze, minting error Medal Alignment in coin of XX centavos 1951 of bronze, World Coins Portugal KM#584 (The normal imaginary minting axis of this coin is horizontal (↑↓), however, due to human error in assembling the dies, that is, the incorrect placement of the dies in the press, there were coins that were minted with deviated axes, this being one of those errors in this case, medal alignment (↓↓).