1913 JAMA reference https://books.google.com/books?id=xZw1AQAAMAAJ&pg=PA1072&lpg=PA1072&dq=gelpi+retractor+inventor&source=bl&ots=fB4u-Ra-dj&sig=1oUoIi3wezr8w9TzWsdgD7ymyw0&hl=en&sa=X&ved=0ahUKEwjTytzZ-L_bAhWFslkKHW5VD4k4HhDoAQhDMAY#v=onepage&q=gelpi%20retractor%20inventor&f=false