http://onlinelibrary.wiley.com/doi/10.1002/smll.200500516/abstr Preparation of Monodisperse, Submicrometer Carbon Spheres by Pyrolysis of Melamine–Formaldehyde Resin Small Volume 2, Issue 7, July 2006, Pages: 859–863, Bettina Friedel and Siegmund Greulich-Weber Article first published online : 24 MAY 2006, DOI: 10.1002/smll.200500516