A. ABOOD, S.; H. KHATHYER, F. Measurement of Specific Activity of Dihydrofolate Reductase (DHFR) Enzyme and Determination of Folate Content Extracted from UV-Exposed Stem- Derived Callus of Sunflower (Helianthus annuus L.). Rafidain Journal of Science, [S. l.], v. 23, n. 6, p. 1–11, 2012. DOI: 10.33899/rjs.2012.59598. Disponível em: https://jwups.uomosul.edu.iq/index.php/rsci/article/view/46606. Acesso em: 28 sep. 2025.