1. Wrist support during typing — a controlled, electromyographic study
2. COLALANCIA , M. , GERARD , M. , LATKO , W. , and STANUSH , J. 1993 , Effects of keyboard resistance and typing speed on surface EMG measurements , unpublished laboratory report , University of Michigan , Ann Arbor , MI .
3. Discomfort and load on the upper trapezius muscle when operating a word processor
4. HALL , E. 1922 , Typewriter keyboard , US Patent No. 1,468,566 .