Daveler, B. ., Wang, H. ., Gebrosky, B. ., Grindle, G. ., Schneider, U. ., & Cooper, R. . (1969). Integration of Pneumatic Technology in Powered Mobility Devices. Topics in Spinal Cord Injury Rehabilitation, 23(2), 120-130. https://doi.org/10.1310/sci2302-120 (Original work published 1969)