In DGSD, no fewer than three groups possessed libraries of martial arts manuals that encompassed nearly all the techniques of wulin at the time: Lee Chou Sui's library in the cave at Boundless Mountain in Dali, Madame Wong's collection at Camellia Manor in Gusu, and the Mo Yung Family's library (also in Gusu).
I'm guessing that Madame Wong had that collection because she was Lee Chou Sui's daughter and thus, her mother provided her with a copy of all the manuals that she (Lee) had obtained. The Mo Yungs being related by marriage to the Wongs, they probably acquired third generation copies of the manuals from the Wongs before the falling out between the two families. Is this so?
Additionally, how did Lee Chou Sui acquire all those manuals in the first place? Martial arts techniques are closely guarded secrets in wulin. How was Lee Chou Sui able to obtain all those manuals?
Two notable exceptions whose techniques did not end up in the Lee, Wong, or Mo Yung libraries were the Deun Royal Family of Dali (1 Yeung Finger Technique and 6 Mak Divine Swords Technique) and the Beggar's Union (Hong Lung 28 Palms and Dog Beating Stick Technique). How did the Deuns and the Beggar's Union avoid having their techniques stolen? Was it because the Deun princes and the Beggar's Union Chiefs were too formidable for even Lee Chou Sui to overcome (unlikely, it would seem)?
Finally, did the Shaolin Temple have a similar library in which they had manuals not only of Shaolin's own martial arts techniques, but also those of most other sects and schools? If so, how did Shaolin acquire these manuals?