Traditionally, the most commonly used source of bibliometric data is the Thomson ISI Web of Knowledge, in particular the (Social) Science Citation Index and the Journal Citation Reports, which provide the yearly Journal Impact Factors. This database used for the evaluation of researchers is not advantageous in the humanities, mainly because books, conference papers, and non-English journals, which are an important part of scientific activity, are not (well) covered. This paper presents the use of an alternative source of data, Google Scholar, and its benefits in calculating citation metrics in the humanities. Because of its broader range of data sources, the use of Google Scholar generally results in more comprehensive citation coverage in the humanities. This presentation compares and analyzes some international case studies with ISI Web of Knowledge and Google Scholar. The fields of economics, geography, social sciences, philosophy, and history are focused on to illustrate the differences of results between these two databases. To search for relevant publications in the Google Scholar database, the use of "Publish or Perish" and of CleanPoP, which the author developed to clean the results, are compared.