APA (7th ed.) Citation

Krugman, P. R. (1993). First nature, second nature and metropolitan location. [s.n.].

Chicago Style (17th ed.) Citation

Krugman, Paul R. First Nature, Second Nature and Metropolitan Location. [S.l.]: [s.n.], 1993.

MLA (9th ed.) Citation

Krugman, Paul R. First Nature, Second Nature and Metropolitan Location. [s.n.], 1993.

Warning: These citations may not always be 100% accurate.