[1] UNIV OKLAHOMA,CHILDRENS MEM HOSP,HLTH SCI CTR,DEPT PEDIAT,OKLAHOMA CITY,OK 73104
[2] UNIV MINNESOTA,DEPT PEDIAT,MINNEAPOLIS,MN
[3] VET ADM HOSP,MED SERV,OKLAHOMA CITY,OK
[4] UNIV OKLAHOMA,HLTH SCI CTR,DEPT BIOSTATISTICS & EPIDEMIOL,OKLAHOMA CITY,OK