Liscio, A., Palermo, V., Gentilini, D., Nolde, F., Müllen, K., & Samori, P. (2006). Quantitative measurement of the local surface potential of pi-conjugated nanostructures: A Kelvin probe force microscopy study. Advanced Functional Materials, 16(11), 1407-1416. doi:10.1002/adfm.200600145.