The various references in the WUPPOL Database are as follows:

 A. 	For stellar objects taken from the merged polarization and UV 
        photometry catalogs, the codes for the references are:

	1. For the Polarization reference:

		1 = Appenzeller 1966, Zs.f. Astrophysik, 64, 269
		2 = Appenzeller 1968, Ap.J., 151, 907
		3 = Behr 1959, Gottingen, 7, 185
		4 = Hall 1958, Publ. U.S. Naval Obs., Vol.17, No.VI, p 275
		5 = ?
		6 = ? 
		7 = Hiltner 1956, Ap.J. Suppl., 2, 389
		8 = Klare, Neckel & Schnur 1972, A.&A. Suppl., 5, 239
		9 = Mathewson and Ford 1970, Mem.R.A.S., 74, 139
	        0 = ?
	        A = McLean and Brown 1978, A.&A., 69, 291
	        B = Poeckert and Marlborough 1976, Ap.J., 206, 182
	        C = Coyne 1971, Trieste Colloq. on Supergiant Stars, ed. 
                                M. Hack (Trieste),p 93
	        D = Coyne, Gehrels and Serkowski XXVI. 1974, A.J., 79, 581
	        E = Serkowski, Mathewson and Ford 1975, Ap.J., 196, 261
		S = Schroeder 1976, A.&A. Suppl., 23, 125
		U = Unknown

	2. For the UV Reference:

		T = TD1 data (2365/1565) Thompson et. al 1978, SRC
		A = ANS data (2500/1550) Wesselius et. al 1982, A.&A. Suppl.,
                                         49, 427
		B = Both of the above (ANS magnitudes used)
		N = No UV data

 B. 	For quasi stellar objects and BL Lac objects the refs are:

		S = Stockman,H.S. & Angel J.R.P. 1978, Ap.J., 220, L67.
		M = Moore,R.L. & Stockman,H.S. 1981, Ap.J., 243, 60.
		A = Angel and Stockman 1980, Ann.Rev.A.&Ap.18,321.

	Additional (e.g. RA, DEC, Z)  data for these objects is taken from:

		Hewitt,A. & Burbidge,G. 1980, Ap.J.Suppl., 43, 57.


	An extensive discussion of extragalactic object polarization is
	to be found in:

	Angel,J.R.P. & Stockman,H.S. 1980, Ann.Rev.A.&Ap. 18, 321.
                                                                     
 C.	Data for selected Seyfert Galaxies is from:

		K = Khachikian,E.Y. & Weedman,D.W. 1974, Ap.J., 192, 581.
		M = Maza, Martin & Angel 1978 Ap.J., 224, 368.