X Chen, McGurk, SL , Davies, MC , Roberts, CJ , Shakesheff, KM , Tendler, SJB , Williams, PM , Davies, J, Dawkes, AC , and Domb, A. 1998. “Chemical And Morphological Analysis Of Surface Enrichment In A Biodegradable Polymer Blend By Phase-Detection Imaging Atomic Force Microscopy”. Macromolecules, 31, 7, Pp. 2278–2283.