Use libraries and databases to research scientific citation and look for patterns of how it changed over time.
Come up with a hypothesis or argument concerning the history of scientific citation. For example, you could make an argument as to how a set of factors caused scientific citation to change over time. It is not sufficient for the thesis to merely describe the history of scientific citation.
Write your thesis statement. Your thesis statement should present your hypothesis or argument in one or a few sentences.
Write a review of the literature, which will be the second section of your thesis. A review of the literature summarizes the research that has been done on your topic by other people. Follow this with the methods section, which describes your research methodology.
Use your library and database research to write the results section of your thesis. Follow this with a discussion section, in which you evaluate your thesis statement in light of your results.
Write the introduction and conclusion to your thesis. The introduction should discuss the topic of scientific citation broadly and then narrow in to your thesis statement. The conclusion should summarize your thesis and provide a broader context such as why your thesis topic is important or which further research should be done.
Proofread your thesis before turning it in. Ask your adviser for his or her input. Allow enough time for revisions before you have to defend your thesis.