National Conference of State Legislatures (NCSL) 

Federation of Tax Administrators (FTA) 

North Eastern States Tax Officials Association (NESTOA) 

Southeastern Association of Tax Administrators (SEATA) 

Western States Association of Tax Administrators (WSATA) 

Midwest States Association of Tax Administrators (MSATA) 

Streamlined Sales Tax Project (SSTP) 

Multistate Tax Commission (MTC) 

Database of State Incentives for Renewables & Efficiency 

State Government Affairs Council (SGAC) 

State Legislatures 

State Tax Agencies 

Tax Foundation 

TAXSites.com 

Mobile Workforce Coalition

National Governors Association (NGA) 

Multistate Associates