Data Used
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* Optical: CFHTLS Wide & Deep downloaded from Terapix. Information is available in HeDaM at http://vohedamtest.lam.fr/browse/cfhtls/q

* VIDEO: VIDEO-all_2016-04-14_fullcat_errfix.fits (private catalogue). Information available from http://www-astro.physics.ox.ac.uk/~video/internal/Data_Access_internal.html. See also readme.video

* VIKING: Information on columns: http://horus.roe.ac.uk/vsa/www/VIKINGv20160406/VIKINGv20160406_TABLE_vikingSourceSchema.html
* VHS: See http://horus.roe.ac.uk/vsa/www/VHSv20161007/VHSv20161007_TABLE_vhsSourceSchema.html
* DXS: See http://wsa.roe.ac.uk/www/WSA_TABLE_dxsSourceSchema.html

* Spitzer (SWIRE & SERVS). Information: http://vohedamtest.lam.fr/browse/df_spitzer/q