中国科学技术信息研究所--国家工程技术数字图书馆

walden university.(68)

university of washington.(37)

capella university.(33)

university of minnesota.(27)

harvard university.(26)

university of california los angeles.(25)

university of michigan.(24)

the university of north carolina at chapel hill.(23)

university of toronto (canada).(22)

the university of wisconsin - madison.(19)

columbia university.(17)

iowa state university.(17)

state university of new york at buffalo.(16)

utica college.(16)

arizona state university.(15)

indiana university.(15)

the university of chicago.(15)

university of pennsylvania.(15)

city university of new york.(14)

michigan state university.(14)

new york university.(14)

state university of new york at albany.(14)

university of illinois at urbana-champaign.(14)

the university of alabama at birmingham.(13)

purdue university.(12)

the pennsylvania state university.(12)

university of california berkeley.(12)

utah state university.(12)

colorado state university.(11)

the chinese university of hong kong (hong kong).(11)