"Principles of Economics" by Alfred Marshall is a landmark work in the field of economics. First published in 1890, the book is still considered a classic and a foundational text in the study of microeconomics and macroeconomics.

The book presents a comprehensive and systematic analysis of economic theory, covering topics such as supply and demand, production theory, cost theory, perfect competition, monopoly, imperfect competition, factor markets, distribution theory, international trade, economic welfare, utility, elasticity, general equilibrium theory, economic growth, monetary theory, financial markets, and economic development.

Marshall's approach to economics was highly influential in the development of the discipline, emphasizing the importance of empirical observation and analysis, as well as a focus on marginal analysis and the interdependence of different economic variables.

Written in a clear and accessible style, "Principles of Economics" is an essential resource for students, scholars, and practitioners of economics, providing a solid foundation in the principles of economic theory and their practical applications.