Star Formation Rate

How does one analytically estimate star formation rate in a plasma cloud? Could someone lead me to original references? Kennicutt-Schmidt Law, I guess, is empirical.

$$\rm{SFR} \sim \epsilon \cdot M_{H} \cdot t_\rm{dyn}^{-1}$$
Where $\epsilon$ is the efficiency factor (maybe ~0.1), and $t_\rm{dyn}$ is the dynamical time.