Volkmer, T., Wiesner, U., Brombacher, L., & Spiess, H. W. (1996). Molecular dynamics in polystyrene from electron spin resonance (ESR) measurements: Comparison between spin-probes and -labels attached to the chain ends. Macromolecular Chemistry and Physics, 197(3), 1121-1134. doi:10.1002/macp.1996.021970329.