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	Hassan S.M. 1972, Mem. Soc. Astr. Italiana 43,117

R4	Pena J.H., Peniche R. 1994, Rev. Mex. Astr. Astrofis. 28, 139

Back to the form