1. The Lower Extremity Functional Scale (LEFS): Scale Development, Measurement Properties, and Clinical Application. North American Orthopaedic Rehabilitation Research Network;Binkley;Physical Therapy,1999
2. The Centers for Medicare & Medicaid Services 2013 Roadmap for Implementing Value Driven Healthcare in the Traditional Medicare Fee-for-Service Program http://www.cms.gov/Medicare/Quality-Initiatives-Patient-Assessment-Instruments/QualityInitiativesGenInfo/Downloads/VBPRoadmap_OEA_1-16_508.pdf
3. Centers for Medicare & Medicaid Services 2012 Implementing the Claims-Based Data Collection Requirement for Outpatient Therapy Services. Section 3005(g) of the Middle Class Tax Relief and Jobs Creation Act (MCTRJCA) of 2012 (CMS-100-04, Transmittal 2622). Federal Register 77, No. 222 (Novemeber 16, 2013), pp. 68958-68978 https://www.cms.gov/Regulations-and-Guidance/Guidance/Transmittals/Downloads/R2622CP.pdf