Author,Title,Journal,ISSN,Publisher,Date,Volume,Number,Page,URL,URL(DOI) Ishikawa Toshiaki,Experiments of Free-Fall in the Air,Journal of the Physics Education Society of Japan,0385-6992,The Physics Education Society of Japan,1990,38,2,73-75,https://cir.nii.ac.jp/crid/1390282679491217408,https://doi.org/10.20653/pesj.38.2_73