Author	Title	Journal	ISSN	Publisher	Date	Volume	Number	Page	URL	URL(DOI)
Okuma K.	Studies of the Cultural Area in the World History	社会科研究	0289856X	Japanese Educational Research Association for the Social Studies (JERASS)	1972-03-25		20	85-91	http://ci.nii.ac.jp/naid/110007867432/en/