Author,Title,Journal,ISSN,Publisher,Date,Volume,Number,Page,URL,URL(DOI) Matsuda Fumiko and Hashimoto Iwao and Matsuda Michihiko,"Development of concepts of Time, Space and Velocity (IV) : methods",Research bulletin of educational sciences Naruto University of Teacher Education,13434403,Naruto University of Education,1990,5,,285-297,https://cir.nii.ac.jp/crid/1570572701805489536,