EXHIBIT A AGREEMENT TO FILE JOINT ACQUISITION STATEMENTS AGREEMENT made this 13th day of November, 2007 by and between DELAWARE GROUP EQUITY FUNDS I, DELAWARE GROUP EQUITY FUNDS II, DELAWARE GROUP EQUITY FUNDS III, DELAWARE GROUP EQUITY FUNDS IV,...Agreement to File Joint Acquisition Statements • November 13th, 2007 • Delaware Management Holdings Co Inc • Investment advice
