RT Journal Article SR Electronic T1 Practice-based Research Networks (PBRNs) in the United States: Growing and Still Going After All These Years JF The Journal of the American Board of Family Medicine JO J Am Board Fam Med FD American Board of Family Medicine SP 541 OP 545 DO 10.3122/jabfm.2015.05.150227 VO 28 IS 5 A1 Hickner, John A1 Green, Larry A. YR 2015 UL http://www.jabfm.org/content/28/5/541.abstract AB