1. Comptes Rendus des Séances de la Onziéme Conférence Générale des Poids et Mesures,1960
2. ISO Recommendation R31,1960
3. British Standard 3763:1964, The International System (SI) Units. B.S.I., London.
4. The International System of Units (SI Units);Bigg;Br. J. Appl. Phys.,1964
5. Changing to the Metric System. Conversion factors, symbols and definitions;Anderton,1965