Cross sections and transport of O− in H2O vapour at low pressures Vladimir Stojanović, Zoran Raspopović, Dragana Marić and Zoran Lj. Petrović Eur. Phys. J. D, 69 3 (2015) 63 Published online: 06 March 2015 DOI: 10.1140/epjd/e2015-50720-9