APA (7th ed.) Citation

Freeman, R. B. (1995). Working for nothing: The supply of volunteer labor. National Bureau of Economic Research.

Chicago Style (17th ed.) Citation

Freeman, Richard B. Working for Nothing: The Supply of Volunteer Labor. Cambridge: National Bureau of Economic Research, 1995.

MLA (9th ed.) Citation

Freeman, Richard B. Working for Nothing: The Supply of Volunteer Labor. National Bureau of Economic Research, 1995.