Collecting and interpreting qualitative materials - Denzin, Norman K.; Lincoln, Yvonna S.; Engels, Jeremy D.; Adams St. Pierre, Elizabeth; Peräkylä, Anssi; McKenzie, Kathryn Bell; House, Ernst R.; Richardson, Laurel; Frey, James H.; Denzin, Norman K.; Scheurich, James Joseph; Angrosino, Michael V.; et al. (SAGE, 2008)