A study of trade & economic development of the Gulf countries 并列题名：A study of trade & economic development of the Gulf countries Theory of economic development of large countries 并列题名：Theory of economic development of large countries New phase of cluster-based economic development in western countries a study of the fundamentals of economic development and cultural change 并列题名：New phase of cluster-based economic development in western countries a study based on economic decision quality of the poor households Study on foreign economic and trade strategy of five asean countries