erc: who: Blodgett, John E. what: Environmental Protection: How Much it Costs and Who Pays when: 19970416 where: https://digital.library.unt.edu/ark:/67531/metadc822360/ erc-support: who: University of North Texas Libraries what: Permanent: Stable Content: when: 20081203 where: https://digital.library.unt.edu/ark:/67531/