Before revision:  In this paper, we sketch for the first time the evolution of knowledge bases for key LCETs and show how technological interdependencies change in time. We use data covering almost all US patents as well as scientific articles published in the past two centuries to quantify the history of LCETs and their dependence on science.
After revision:  Using data covering almost all US patents as well as scientific articles published in the past two centuries to quantify the history of LCETs and their dependence on science.