Supatra Kaewkongnok และ Phusit Wonglorsaichon. (2023) The Effective Ways to Increase the Sales of Telemarketing. <i>Journal of Family Business and Management Studies</i>, <i>15</i>(1), 141-154.Supatra Kaewkongnok และ Phusit Wonglorsaichon. "The Effective Ways to Increase the Sales of Telemarketing.". Journal of Family Business and Management Studies 15 (2023):141-154.Supatra Kaewkongnok และ Phusit Wonglorsaichon. The Effective Ways to Increase the Sales of Telemarketing. University of the Thai Chamber of Commerce:ม.ป.ท. 2023.