URL：https://m.media-amazon.com/images/I/419JBlzGRvL._SR600,315_PIWhiteStrip,BottomLeft,0,35_SCLZZZZZZZ_FMpng_BG255,255,255.jpg
掲載元：http://www.sciencebooksonline.info/x/engineering/medicine/mathematics/mathematics/engineering/physics/engineering/computer-science/databases-information-retrieval.html
