Gaya APA

Friman, T, G, D, E, A, M. (2014). Handbook of Sustainable Travel . New York: Springer Science Business Media, Inc..

Gaya MLA

Friman, Tommy, Ga¨rling,, Dick, Ettema, And, Margareta. "Handbook of Sustainable Travel". New York: Springer Science Business Media, Inc., 2014. Text.