A STUDY OF RESONANCE STRUCTURES IN ELASTIC ELECTRON SCATTERING BY MOLECULES IN THE BACKWARD DIRECTION Brygida Mielewska+, George C. King++, Mariusz Zubek+ + Department of Physics of Electronic Phenomena, Technical University, 80-952 Gda=F1sk, Poland ++ Department of Physics and Astronomy, Schuster Laboratory, Manchester University, Manchester M13 9PL, UK Resonance structures corresponding to the 2(sigma)+ state at 10.044 eV in carbon monoxide and the 2(sigma)g+ state at 11.499 eV in nitrogen have been studied in elastic electron scattering over the angular range from 95deg to 180deg using the magnetic angle-changing technique.