Lyubomirova, V.; Belovezhdova, I.; Kamusheva, A.; Ignatov, P.; Tuhchiev, P. Optimization of Solid-Phase Extraction and GC-MS/MS Determination of PAHs in Bulgarian Sewage Sludge. C. R. Acad. Bulg. Sci. 2026, 79, 312–320.