Midgap states in corrugated graphene: Ab initio calculations and effective field theoryT. O. Wehling, A. V. Balatsky, A. M. Tsvelik, M. I. Katsnelson and A. I. LichtensteinEPL, 84 1 (2008) 17003DOI: https://doi.org/10.1209/0295-5075/84/17003