2018-12-212018-12-211987-01-06https://hdl.handle.net/2152.3/11087invoice and letter to Whitmore Enterprise for contract and development of treadmillDr. William ThorntonresearchexercisetreadmillinvoicepaymentWhitmore EnterprisesKrugTreadmill_71-81_2_FirstPymtInvoice2ndGenTM_01.06.87