Wolinsky FD, Liu L, Miller TR, An H, Geweke JF, Kaskie B, Wright KB, Chrischilles EA, Pavlik CE, Cook EA, Ohsfeldt RL, Richardson KK, Rosenthal GE, Wallace RB. Emergency department utilization patterns among older adults. J Gerontol A Biol Sci Med Sci. 2008 Feb; 63(2):204-9.