中国科学技术信息研究所--国家工程技术数字图书馆

indiana university.(15)

university of michigan.(13)

university of toronto (canada).(13)

michigan state university.(12)

the university of wisconsin - madison.(10)

university of california los angeles.(10)

city university of new york.(9)

iowa state university.(9)

syracuse university.(9)

university of washington.(9)

princeton university.(8)

northwestern university.(7)

purdue university.(7)

rutgers the state university of new jersey - new brunswick.(7)

the university of arizona.(7)

university of pittsburgh.(7)

harvard university.(6)

indiana university of pennsylvania.(6)

the university of iowa.(6)

the university of north carolina at chapel hill.(6)

the university of north carolina at charlotte.(6)

university of california riverside.(6)

university of southern california.(6)

yale university.(6)

new york university.(5)

northeastern university.(5)

northern illinois university.(5)

stanford university.(5)

the university of chicago.(5)

university of california berkeley.(5)