title: Sigma- and pi-electron delocalization: focus on substituent effects.
authors.affiliation: Department of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland. tmkryg@chem.uw.edu.pl
authors.forename: Tadeusz Marek
authors.initials: TM
authors.lastname: Krygowski
authors.forename: Beata Tamara
authors.initials: BT
authors.lastname: Stepień