Not really in any one place, though there are fragments here and there throughout jan Sonja's (few) writings and jan Pije's and various others. The best guess is that a casual acquaintance with the idea of Daoism was a part of the inspiration for tp: simplicity, limited resources, etc. Any attempt to find connections between the details of Daoism as a developed philosophy (or even the aphorisms of Laozi and Zhuangzi) and any details of tp vocabulary or grammar seem bound to failure. Daoism is, after all, a mystical system, which tends to place all problems on the lap of language: "once you call something good, evil exists" and so on. So using it as a framework for a language is at least counterintuitive and probably heretical. But the connnection does get a lot of people to read the DDJ and occasionally gets a DDJ reader to try tp, neither bad things.