中国科学技术信息研究所--国家工程技术数字图书馆

the university of chicago.(32)

university of california berkeley.(20)

university of pennsylvania.(19)

new york university.(17)

the johns hopkins university.(16)

university of california los angeles.(16)

columbia university.(13)

harvard university.(13)

university of toronto (canada).(13)

yale university.(11)

princeton university.(10)

university of michigan.(9)

university of washington.(9)

mcgill university (canada).(8)

georgetown university.(7)

the university of utah.(7)

university of california los angeles(7)

temple university.(6)

the university of arizona.(6)

the university of memphis.(6)

university of arkansas.(6)

university of london university college london (united kingdom).(6)

indiana university.(5)

the university of manchester (united kingdom).(5)

the university of north carolina at chapel hill.(5)

the university of wisconsin - madison.(5)

university of california santa barbara.(5)

arizona state university.(4)

brown university.(4)

emory university.(4)