Fong Yim Fun appeared to be the only performer who managed her collaborations with Tang best by getting the film rights and making the films as many times as she wanted to her satisfaction. Lam Kar Sing also appeared to have learnt from Fong when he kept most of his collaborations with librettists published in his troupe's name. On the contrary, Loong was made to record CD for free for librettist in 1980 and could not get other CDs made on her own with that librettist's approval. However, said librettist renamed the pieces and sold them as many times as he wanted on top of royalty payments (1% ?).