hi thanks so much for you help my dissertation topic is limb salvage versus limb amputation due to trauma, i will do this through evaluating the benifits and limitations of lower limb amputation. i would just like to ask you more about gaps in research and limitations of studies that i find. What kind of limitations could there be in a study. For example i can only think of when there is onl one hospital used for the research, or when only one group of participants are used like elderly. thanks so much for your help