Variation Orders and Their Effects of Erbil Governorate Projects. Journal of Engineering, [S. l.], v. 27, n. 5, p. 75–88, 2021. DOI: 10.31026/j.eng.2021.05.06. Disponível em: https://joe.uobaghdad.edu.iq/index.php/main/article/view/1344.. Acesso em: 7 jul. 2024.