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 at buffalo.(31)

university of southern california.(28)

university of south florida.(25)

university of florida.(19)

clemson university.(18)

university of washington.(18)

colorado state university.(17)

texas a&m university.(17)

the university of arizona.(16)

the university of utah.(16)

university of california berkeley.(16)

state university of new york college of environmental science and forestry.(15)

university of california santa barbara.(15)

university of minnesota.(15)

university of south carolina.(15)

george mason university.(14)

michigan state university.(14)

oklahoma state university.(14)

southern illinois university at carbondale.(14)

the florida state university.(14)

michigan technological university.(13)

the ohio state university.(13)

arizona state university.(12)

the university of alabama.(12)

iowa state university.(11)

purdue university.(11)

the university of north dakota.(11)

university of arkansas.(11)

university of california davis.(11)

university of kansas.(11)