Gaya APA

Elkington, J., Hartigan, P. (2008). The power of unreasonable people : how social entrepreneurs create markets that change the world (First edition). Boston, Massachusetts: Harvard Business Press.

Gaya MLA

Elkington, John., Hartigan, Pamela. "The power of unreasonable people : how social entrepreneurs create markets that change the world". First edition Boston, Massachusetts: Harvard Business Press, 2008. Text.