约 28,500,000 个结果
在新选项卡中打开链接
What Is a Research Design | Types, Guide & Examples - Scribbr
Research Design – Types, Methods and Examples
Study designs in biomedical research: an introduction to the ...
Study designs: Part 1 – An overview and classification - PMC
What is a Research Design? Definition, Types, Methods and ...
What is a study design? - California Learning Resource Network
What Is a Research Design: Types, Characteristics & Examples
Understanding Research Study Designs - PMC - PubMed Central …