Improved positions and some optical identifications for 451 4C radio sources between declinations 4° and 20° /

Autor Wills, Derek, Bolton, J. G., 1922-1993
Vydáno 1969

External galaxies and quasi-stellar objects : International astronomical Symposium no. 44 held in Uppsala, Sweden, 10-14 August 1970 /

Vydáno 1972