ON THE SOLVABILITY OF BOUNDARY VALUE PROBLEMS WITH GENERAL CONDITIONS FOR THE TRIHARMONIC EQUATION IN A BALL - Koshanov, Bakytbek; Shynybayeva, Nazym; Koshanova, Maira; Oralbekova, Nazerke (Vestnik KazNU. Serii͡a︡ matematika, mekhanika, informatika, 2025)