SI, CGSG, and ch units: metrology and special relativity
  Invited report at the 8th Meeting of the Working Group ``Base units and fundamental constants'' of the French Academy of Sciences. June 14, 2004.   The text consists of seven sections:   1. Great importance of SI. 2. The necessity of updating SI. 3. Special relativity: four-dimensional quantities. 4. Maxwell equations in vacuum in CGSG units. 5. Maxwell equations in vacuum in SI. 6. $c \hbar$ units. 7. Systems CGSG and $c \hbar$ should be legalized. 
L.B. Okun