TY - JOUR AU - P. Schneider BT - The Astrophysical Journal DA - Jan-05-1987 DO - 10.1086/184881 PY - 1987 EP - L7 T2 - The Astrophysical Journal TI - The amplification bias by gravitational lensing on observed number counts of quasars - Effects of a finite source size UR - http://articles.adsabs.harvard.edu/full/1987ApJ...316L...7S VL - 316 SN - 0004-637X ER -