Here&#x27;s a link for the (download-able) pdf: <a href="http:&#x2F;&#x2F;www.physics.utah.edu&#x2F;~starykh&#x2F;phys7640&#x2F;Lectures&#x2F;FeynmansDerivation.pdf" rel="nofollow">http:&#x2F;&#x2F;www.physics.utah.edu&#x2F;~starykh&#x2F;phys7640&#x2F;Lectures&#x2F;Feynm...</a>