In Google Scholar the resource with the most citations floats to the top. That may be a seminal article or it may cite a seminal article.
Over time, an important paper is likely to be cited by many researchers, and the number of times a paper is cited is a popular measure of a paper’s quality, value, and impact on a research topic or discipline. When citation data is collected it not only lets a searcher look for earlier publications, but enables one to follow the development of research forward in time by looking at papers that refer back to a specific article. This network of relationships between authors, papers, and ideas is a valuable adjunct to traditional literature searching.