1. U.S. NATIONAL BUREAU OF STANDARDS TECHNICAL NEWS BULLETIN 44: 199 (1960).
2. U.S. NATIONAL BUREAU OF STANDARDS TECHNICAL NEWS BULLETIN 46: 34 (1962).
3. U.S. NATIONAL BUREAU OF STANDARDS TECHNICAL NEWS BULLETIN 48: 38 (1964).
4. U.S. NATIONAL BUREAU OF STANDARDS TECHNICAL NEWS BULLETIN 48: 209 (1964).
5. >U.S. NATIONAL BUREAU OF STANDARDS MONOGRAPH 1960 10 The 1958 He 4 scale of temperatures