Literature Reference: 河畔青芜堤上柳，为问新愁，何事年年有？—— 《鹊踏枝·谁道闲情抛掷久》 By the riverbank, green grass and willows on the dyke ask about new sorrows, why do they return every year? Source from 'Que Ta Zhi·Who Says Idle Feelings Are Long Discarded?'.