Effects of air pollution and acid rain on forest decline : oversight hearing before the Subcommittee on Mining, Forest Management, and Bonneville Power Administration of the Committee on Interior and Insular Affairs, House of Representatives, Ninety-eighth Congress, second session on effects of air pollution and acid rain on forest decline, hearing held in Washington, DC, June 7, 1984. (U.S. G.P.O.,, 1984)