% "The VLBA Calibrator Survey - VCS1",
   \bibitem[Beasley et~al.(2002)]{vcs1} Beasley,~A.~J., Gordon,~D.,
      Peck,~A.~B., Petrov,~L., MacMillan,~D.~S., Fomalont,~E.~B., \&
      Ma,~C. 2002, \apjs, 141, 13

   % "The Second VLBA Calibrator Survery: VCS2",
   \bibitem[Fomalont et~al.(2003)]{vcs2}
      Fomalont,~E., Petrov,~L., McMillan,~D.~S., Gordon,~D., Ma,~C.
      2003, \aj, 126, 2562

   % "The Third VLBA Calibrator Survery - VCS3",
   \bibitem[Petrov et~al.(2005)]{vcs3}
      Petrov,~L., Kovalev,~Y.Y., Fomalont,~E., Gordon,~D. 2005, \aj, 129, 1163.

   % "The Fourth VLBA Calibrator Survery - VCS4",
   \bibitem[Petrov et~al.(2006)]{vcs4}
      Petrov,~L., Kovalev,~Y.Y., Fomalont,~E., Gordon,~D. 2006, \aj, 131, 1872.

   % "The Fifth VLBA Calibrator Survery - VCS5",
   \bibitem[Kovalev et~al.(2007)]{vcs5}
      Kovalev,~Y.Y., Petrov,~L., Fomalont,~E., Gordon,~D. 2007, \aj, 133, 1236.

   % "The Sixth VLBA Calibrator Survey -- VCS6",
   \bibitem[Petrov et~al.(2008)]{vcs6}
      Petrov,~L., Kovalev,~Yu.Y., Fomalont,~E., and Gordon,~D., 2008, 
      \aj, 136, 580.