@article{oai:air.repo.nii.ac.jp:00005267,
 author = {MINATO, Saburoh and 湊, 三郎},
 issue = {10},
 journal = {東北数学教育学会年報},
 month = {Mar},
 pages = {3--8},
 title = {On the test- retest reliability of the scale of the difficulty of numbers grasped as connotative meaning experienced by forth and sixth grade pupils},
 year = {1979}
}