中国科学技术信息研究所--国家工程技术数字图书馆

harvard university.(14)

princeton university.(10)

university of california los angeles.(10)

yale university.(10)

the johns hopkins university.(8)

new york university.(7)

the university of chicago.(7)

university of pennsylvania.(6)

brown university.(5)

university of kansas.(5)

university of michigan.(5)

georgetown university.(4)

stanford university.(4)

texas a&m university.(4)

university of california santa barbara.(4)

university of pennsylvania(4)

university of virginia.(4)

university of washington.(4)

arizona state university.(3)

fordham university.(3)

harvard university(3)

indiana university.(3)

rutgers the state university of new jersey - new brunswick.(3)

syracuse university.(3)

the catholic university of america.(3)

the university of north carolina at chapel hill.(3)

the university of wisconsin - madison.(3)

university of california berkeley.(3)

university of california los angeles(3)

university of minnesota.(3)