Smith, R., Beaverstock, J., & Taylor, P. (1999). A roster of world cities. Cities: The International Journal of Urban Policy and Planning, 16(6), pp. 445-458. doi:10.1016/S0264-2751(99)00042-6

Smith, Richard, J.V Beaverstock, and P.J Taylor. "A Roster of World Cities." Cities: The International Journal of Urban Policy and Planning 16, no. 6 (1999): 445-458.

Smith, Richard, J.V Beaverstock, and P.J Taylor. "A Roster of World Cities." Cities: The International Journal of Urban Policy and Planning 16.6 (1999): 445-458.