International Competition , R & D Investment Patterns , and Endogenous Sunk Costs in Canada and the United States , 1987-2002Daniel Ershovsemanticscholar(2015)引用 0|浏览1暂无评分AI 理解论文溯源树样例生成溯源树,研究论文发展脉络Chat Paper正在生成论文摘要