Techniques for searching Japanese documents using not only library databases, but also information provided through smartphones, among others are reviewed. The main target of this article was university studentsmajoring in the humanities. Results identified the following issues. Firstly,classifying different information sources from the perspective of time considerations indicated two types of information sources: sources that needed to provide current, and sources that needed to provide comprehensiveinformation. Secondly, advantages and disadvantages of newspapers, journals, theses, books, and white papers are identified. Thirdly, techniques for searching documents using these information sources are introduced.