“Double-activated nucleophilic aromatic substitution polymerization by bis-ortho-trifluoromethyl groups to soluble para-poly(biphenylene oxide)” by Suhyeon Lee, Rokam Jeong, Myungeun Seo, and Hee-Seung Lee was published in Polymer.
Link: https://www.sciencedirect.com/science/article/pii/S0032386119311292