Yotsuya Otsuka's Yosyu Series. This is a two-book set of the Exercise Workbook and Answer Explanation for Social Studies, 4th Grade, Lower Volume. - Title: Exercise Workbook Social Studies 4th Grade, Lower Volume - Publisher: Yotsuya Otsuka - Grade: 4th Grade, Lower Volume - Number of Books: 2-book set Thank you for viewing. This is the Exercise Workbook for the Yosyu Series Social Studies, Lower Volume. There are no markings. Answer sheets for lessons 11-14 are missing, having been cut out. Within the Answer Explanation, the "Let's Summarize!" sections for lessons 9 and 12-18 are missing. I am also selling other Yosyu Series books, so if you would like to purchase multiple items, please comment. Please purchase if you understand the condition of the used item.