A good book that provides a quite detailed overview of some physical modeling algorithms (and tons of other synthesis algorithms) is The Computer Music Tutorial

A good book that provides a quite detailed overview of some physical modeling algorithms (and tons of other synthesis algorithms) is The Computer Music Tutorial by C. Roads. With regards to Karplus-Strong for example, it provided an in-depth enough explanation of the algorithm for for me to base an implementation solely on it. There is another description of a flute instrument model, using noise, filters and delay lines.