NED object is NGC 3963; Reference is  1997AJ....114...77N

   FIG. 9. NGC 3963 (a) Contours of constant H I flux overlaid on a greyscale
 of the Gunn r optical image of NGC 3958~63. NGC 3958 is to the southwest and
 NGC 3963 is the face on spiral to the northeast. The H I data are naturally
 weighted yielding the synthesized beam shown in the lower left. Contour levels
 are logarithmic with levels at 0.10, 0.14. 0.2O, 0.29, 0.42, 0.60, 0.85, 1.22,
 1.74, 2.48 Jy Bm^-1^  km s^-1^ .