References for the numbering systems

Col	Reference

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

R1	Westerlund B.E. 1987, Astron. Astrophys. Suppl. 70, 311

R2	Piatti A.E., et al. 1998, Astron. Astrophys. Suppl. 127, 423

R3	Clark J.S., et al. 2005, Astron. Astrophys. 434, 949

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