Emerson, Barbara H. Controlling weeds / [electronic resource] / created and designed by the editorial staff of Ortho Books ; project editor, Susan A. Roth ; writer, Barbara H. Emerson ; artist, Amy Bartlett Wright ; photographer, Saxon Holt.. — San Ramon, CA : : Ortho Books, Chevron Chemical Co.,, c1989.. — 95 p. : : col. ill. ; 28 cm.