Poland, S., & Plevyak, L. (2015). US STUDENT PERFORMANCE IN SCIENCE: A REVIEW OF THE FOUR MAJOR SCIENCE ASSESSMENTS. Problems of Education in the 21st Century, Problems of Education in the 21st Century, 64, Discontinuous. presented at the April/2015. doi:https://doi.org/10.33225/pec/15.64.53

Pekel, F. O. (2016). PISA RESULTS OR X-RAY FILMS OF EDUCATION SYSTEMS?. Problems of Education in the 21st Century, Problems of Education in the 21st Century, 74, Discontinuous. presented at the December/2016. doi:https://doi.org/10.33225/pec/16.74.04

Edamo, D. L., & Netshitangani, T. (2018). LEADERSHIP, SCHOOL IMPROVEMENT AND EFFECTIVENESS: THE EXPERIENCES OF THE SCHOOLS COMMUNITY IN ETHIOPIA. Problems of Education in the 21st Century, Problems of Education in the 21st Century, 76(5), Continuous. presented at the October/2018. doi:https://doi.org/10.33225/pec/18.76.587

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