U.S. Environmental Protection Agency. Introduction to the national pretreatment program.
Chicago-čujuhus (17. p.)U.S. Environmental Protection Agency. Introduction to the National Pretreatment Program.
MLA-čujuhus (9. p.)U.S. Environmental Protection Agency. Introduction to the National Pretreatment Program.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.