In response to Goddard's claims, von Braun said "at no time in Germany did I or any of my associates ever see a Goddard patent". This was independently confirmed. He wrote that claims about his lifting Goddard's work were the furthest from the truth, noting that Goddard's paper "A Method of Reaching Extreme Altitudes", which was studied by von Braun and Oberth, lacked the specificity of liquid-fuel experimentation with rockets. It was also confirmed that he was responsible for an estimated 20 patentable innovations related to rocketry, as well as receiving U.S. patents after the war concerning the advancement of rocketry. Documented accounts also stated he provided solutions to a host of aerospace engineering problems in the 1950s and 60s.