Invariance of the Bifactor Structure of Mild Traumatic Brain Injury (mTBI) Symptoms on the Rivermead Postconcussion Symptoms Questionnaire Across Time, Demographic Characteristics, and Clinical Groups: A TRACK-TBI StudyStephanie Agtarap, Ava M. Puccio, Laura Campbell‐Sills et al.|Assessment|2020Cited by 27