Bushra Abdulbari Ahmed, and Aymen Ajina. “The Impact of Spending on Research and Development on the Global Patent Index for a Sample of Developed Countries for the Period 2007-2021”. Migration Letters 20, no. S8 (November 4, 2023): 841–863. Accessed November 27, 2024. https://migrationletters.com/index.php/ml/article/view/4657.