中国科学技术信息研究所--国家工程技术数字图书馆

state university of new york college of environmental science and forestry.(50)

university of toronto (canada).(37)

state university of new york at buffalo.(24)

university of alberta (canada).(24)

city university of new york.(17)

university of pennsylvania.(17)

carleton university (canada).(16)

columbia university.(16)

state university of new york at albany.(16)

trent university (canada).(16)

new york university.(15)

university of manitoba (canada).(15)

university of ottawa (canada).(15)

syracuse university.(14)

capella university.(13)

fordham university.(13)

harvard university.(13)

dalhousie university (canada).(12)

mcgill university (canada).(12)

york university (canada).(12)

universite du quebec a rimouski (canada).(11)

university of illinois at urbana-champaign.(11)

cornell university.(10)

rutgers the state university of new jersey - new brunswick.(10)

the university of british columbia (canada).(10)

michigan state university.(9)

queen's university (canada)(9)

the university of north carolina at chapel hill.(9)

universite laval (canada).(9)

university of california los angeles.(9)