1. "A Monetary History of the United States" (1963) - This book argued that monetary policy was the primary factor behind the Great Depression, and that the Federal Reserve's actions (or lack thereof) contributed significantly to the severity of the economic downturn.
2. "Capitalism and Freedom" (1962) - In this book, Friedman advocates for a free market economy, minimal government intervention, and classical liberal ideas such as individual freedom, private property rights, and free trade.
3. "The Counter-Revolution in Monetary Theory" (1970) - This essay criticizes the then-prevailing Keynesian macroeconomic theories and argues for a monetary explanation of the business cycle.

Friedman's ideas had a major impact on economic thought and policy, particularly in the 1970s and 1980s, when his ideas were widely adopted by policymakers and central bankers around the world. He is also known for popularizing the concept of monetarism, which holds that the supply of money is the primary determinant of economic activity and that monetary policy can be used to control inflation and stabilize the economy.