Gravitational mesolensing by King objects and quasar-galaxy associations
  The probability of strong gravitational lensing of distant compact objects by transparent lenses with King mass distributions is calculated. Examples of such lenses are globular clusters, dwarf galaxies, and clusters of hidden mass. The lens masses thus range from 10^3 to 10^9 Solar mass, intermediate between stellar and galactic masses. Taking account of the conic caustic of King lenses and the fractal large-scale distribution of matter along the line of sight, it is possible to explain the correlation between quasars and galaxies as the effect of strong gravitational lensing of the active nuclei of distant galaxies by globular clusters in the halos of nearby galaxies. Observational tests for verifing this mesolensing hypothesis are described. 
Yu. V. Baryshev, Yu. L. Bukhmastova