@book{ BB18500864, author = "Linn, Robert L. and Frederick Ericson", title = "Quantitative methods", publisher = "Macmillan,Collier Macmillan", year = "1990", series = "Research in teaching and learning : a project of the American Educational Research Association", number = "Vol. 2", URL = "https://ci.nii.ac.jp/ncid/BB18500864" }