1. Smetana, F O , "A. semiempirical desciiption of the discharge characteristics of the converging seel ion of a low-density hypersonic nozzle/7J Aerospace Sci 28, 988-989 (1961)
2. Folsom R G , Nozzle characteristics in high vacuum flowsrarefied gas dynamics ' Trans Am Soc Mech Engrs 74, 915-918(1952)
3. Gaskinetics and gasdynamics of orifice flow