 Poly(ethylene terephthalate) by American Chemical Society

Primary source: www.acs.org/molecule-of-the-week/archive/p/poly-ethylene-terephthalate.html

Verified locator: Molecule of the Week, 17 October 2022. Official ACS structural account identifies condensation of ethylene glycol and terephthalic acid. Repeat atom counts and finite-chain examples are explicitly derived in the article.