由宋怀芝编写的《亡羊补牢》讲述了：One night a wolf gnawed a hole in a sheepherder’s pen, and returned the following night to steal a lamb. Reasoning that just one of his sheep had gone missing - while the rest of his flock remained untouched - the sheepherder initially ignored advice to fix the fence. But more of his sheep were snatched in the nights that followed, and he finally realized that he’d best mend the pen.

宋怀芝