Single-particle cryo-EM using alignment by classification (ABC): the structure of Lumbricus terrestris haemoglobin oleh Pavel Afanasyev, Charlotte Seer-Linnemayr, Raimond B. G. Ravelli, Rishi Matadeen, Sacha De Carlo, Bart Alewijnse, Rodrigo V. Portugal, Navraj S. Pannu, Michael Schatz, Marin van Heel