القدير، خالد بن حمد بن عبدالله. (2005). The Causal Relationship between Tourism and International Trade in some Islamic Countries. دراسات اقتصادية، مج5, ع10 ، 31 - 58. مسترجع من http://search.mandumah.com/Record/1095239
القدير، خالد بن حمد بن عبدالله. "The Causal Relationship between Tourism and International Trade in Some Islamic Countries." دراسات اقتصادية مج5, ع10 (2005): 31 - 58. مسترجع من http://search.mandumah.com/Record/1095239