a primer Eckenfelder, W. Wesley creator text Lancaster, Pa Technomic Pub. c1997 monographic xii, 218 p. : ill. ; 24 cm. Factory and trade waste Sewage 628 TEC 1997 A040 Or. 1566765366 http://www.loc.gov/catdir/enhancements/fy0744/97060654-d.html http://www.loc.gov/catdir/enhancements/fy0744/97060654-d.html