Alignment procedure for the VIRGO Interferometer: experimental results   from the Frascati prototype
  A small fixed-mirror Michelson interferometer has been built in Frascati to experimentally study the alignment method that has been suggested for VIRGO. The experimental results fully confirm the adequacy of the method. The minimum angular misalignment that can be detected in the present set-up is 10 nrad/sqrt{Hz} 
D. Babusci, H. Fang, G. Giordano, G. Matone, L. Matone and V.   Sannibale (INFN Frascati)