Coşkun, T., Karagöz, T., Kalkanoğlu, S., Tokatlı, A., Özalp, İ., Thöny, B., & Blau, N. (1999). Guanosine triphosphate cyclohydrolase I deficiency: a rare cause of hyperphenylalaninemia. The Turkish Journal of Pediatrics, 41(2), 231-237. https://doi.org/10.24953/turkjpediatr.1999.3225