1. Y. Matsubara, J.L. Gao, K. Tanida, Y. Hiresaki and M. Kaneko, “An Experimental and Analytical Investigation of 4 K Pulse Tube Refrigerator”, Proceedings of 7th International Cryocooler Conference, (1993), pp. 166–186.
2. J.L. Gao and Y. Matsubara, “4 K Pulse Tube Refrigeration”, Proceedings of 4th JSJS on Cryocoolers and Concerned Topics, (1993), pp. 69–73.
3. J.L. Gao and Y. Matsubara, “Experimental Investigation of 4 K Pulse Tube Refrigerator”, Cryogenics, vol. 34, (1994), pp. 25–30.
4. Y. Matsubara and J.L. Gao, “Novel Configuration of Three-stage Pulse Tube Refrigerator for Temperatures below 4 K”, Cryogenics, Vol. 34 (1994) 259.
5. Y. Matsubara and J.L. Gao, “Multi-staged Pulse Tube Refrigerator for Superconducting Magnet Applications”, Proceedings of the Fifteenth International Cryogenic Engineering Conference, (1994) pp. 155.