A compilation of more than 5000 theories from all disciplines from ancient times to modern. Includes concise and clear definitions. Some theories have been discredited but all have been influential.
A specialized English-Spanish / Spanish-English dictionary covering all aspects of mathematics: applied mathematics, pure mathematics, statistics, algebra, arithmetic, geometry, trigonometry, calculus, topology, probability, game theory, economic mathematics, mathematical logic, etc.
Dictionary of Theories by 
