References for the numbering systems

Col	Reference

---	---------

R1	Hoag A.A., et al. 1961, Publ. US. Nav. Obs. 17, 347  (pe)

R2	Hoag A.A., et al. 1961, Publ. US. Nav. Obs. 17, 347  (pg)

R3	Barbon R., Hassan S.M. 1973, Astron. Astrophys. Suppl. 10, 1

Back to the form