Museum sets info for O'Keefe exhibit February 17, 1999 Share 1 -- WASHINGTON -- The Phillips Collection, an art museum here, said it will require paid, timed-entry tickets to an exhibit of Georgia O'Keeffe paintings that will be on display from April 17 to July 18. Tickets will be for a specific time on the half hour and will cost $12.50 for adults and $9.50 for seniors, students and children ages 12 to 18. Entry to the museum, located at 1600 21st St. NW, will be free for children under 12.Groups may be scheduled on a space-available basis, with tickets reserved for a specific half-hour time slot. For information, call Frampton Tolbert at (202) 387-2151, Ext. 235.Advance group and individual tickets can be purchased through TicketMaster outlets or PhoneCharge at (800) 551-SEAT, starting March 27, for an additional fee.The exhibit, "Georgia O'Keeffe: The Poetry of Things," will travel to Santa Fe, N.M., Dallas and San Francisco.