1. History and origins of cryogenics;Scurlock,1992
2. Sur l'économie du procédé à cascade pour la liquéfaction des gaz;Keesom;Commun Phys Lab Univ Leiden,1933
3. Optimum temperature staging of cryogenic refrigeration system;Jeong;Cryogenics,1994
4. Optimum staging of multistage exo-reversible refrigeration systems;Xuan;Cryogenics,2003
5. Ait-Ali MA et al. Minimum work multistage cascade refrigeration cycles. Cryog Proc Equip in Energy Systems, ASME Press, New York; 1980. p. 119–23.