I am not sure whether this question has been asked on research gate or not. If this topic is already their please send me link. One of the problem we are facing is to check duplication (copied from net or research articles or thesis) in a scientific document. When you get document from students or junior colleagues or from your team members you are always worried whether this is orignal writing or copied from net. Though their are number of software and software on net, it is difficult to trust on these software. I wants to know from my colleagues at this platform what is best way to check duplication. Is their any good server or service which can check duplication with high reliability in scientific writing (can check duplication in literature databases such as PubMed).