中国科学技术信息研究所--国家工程技术数字图书馆

capella university.(40)

walden university.(39)

northcentral university.(26)

george mason university.(24)

georgetown university.(24)

the george washington university.(24)

harvard university.(22)

university of phoenix.(21)

arizona state university.(19)

indiana university.(17)

columbia university.(15)

the university of north carolina at chapel hill.(15)

university of california berkeley.(15)

university of washington.(14)

university of michigan.(13)

michigan state university.(12)

stanford university.(12)

the university of arizona.(12)

virginia polytechnic institute and state university.(12)

state university of new york at buffalo.(11)

the florida state university.(11)

the university of wisconsin - madison.(11)

university of southern california.(11)

george mason university(10)

syracuse university.(10)

university of california los angeles.(10)

university of toronto (canada).(10)

city university of new york.(9)

northern arizona university.(9)

northwestern university.(9)