Ertem, H. Y. (2021). EXAMINATION OF SYSTEM OF TRANSITION TO UPPER-SECONDARY SCHOOLS FROM LOWER-SECONDARY SCHOOLS IN TERMS OF STUDENT, CLASS, AND SCHOOL LEVEL VARIABLES. Problems of Education in the 21st Century, Problems of Education in the 21st Century, 79(2), Continuous. presented at the April/2021. doi:https://doi.org/10.33225/pec/21.79.194