1. Advanced Cryogenics;Bailey,1971
2. The boiling of cryogenic fluids—a survey
3. From Microsemiconductor Corp-Santa Ana, Calif 92704. It must be noted that the MCPD 523 type is only one-sixth as sensitive as the MC 523 A type.
4. From Uniform Tubes, Inc-Collegeville, Pa 215: solid jacketed coaxial cable type UT-85-SS
5. From Mallory: Sonalert, type SC6