Mary Choate and Aaron Brachfeld (31 August 2015). At Home in Nature, a user's guide. Coastalfields Press. p. 303. GGKEY:K5213DDZJD2. Retrieved 21 January 2013.
Direct link to the XLSX file: "2. Table (Excel:890KB)"(xlsx). Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan. 2017-12-25. Archived from the original on 2021-10-13. Retrieved 2021-11-24.
Direct link to the XLSX file: "2. Table (Excel:890KB)"(xlsx). Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan. 2017-12-25. Archived from the original on 2021-10-13. Retrieved 2021-11-24.
Direct link to the XLSX file: "2. Table (Excel:890KB)"(xlsx). Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan. 2017-12-25. Archived from the original on 2021-10-13. Retrieved 2021-11-24.