Middleton, V. T. C., & Hawkins, R. (1998). Sustainable Tourism: A Marketing Perspective (1ed. st.). Butterworth-Heinemann.
Chicago (17e ed.) BronvermeldingMiddleton, Victor T. C., en Rebecca Hawkins. Sustainable Tourism: A Marketing Perspective. 1ed. st. Oxford: Butterworth-Heinemann, 1998.
MLA (9e ed.) BronvermeldingMiddleton, Victor T. C., en Rebecca Hawkins. Sustainable Tourism: A Marketing Perspective. 1ed. st. Butterworth-Heinemann, 1998.