1. Pre-service mathematics teachers’ concept images of radian
2. Avgören, S. (2011). Farklı sınıf seviyelerindeki öğrencilerin kati cisimler (prizma, piramit, koni, silindir, küre) ile ilgili sahip oldukları kavram imajı [Different grade levels students concept image related with solids objects (prism, pyramid, cone, cylinder, sphere)] [Master’s thesis, Gazi University]. Turkish Higher Education Council thesis repository (#290710). https://tez.yok.gov.tr/UlusalTezMerkezi/.