References

• Crawford D.L., Barnes J.V., 1970, AJ 75, 978 NASA ADS
• Olsen E.H., 1983, A&AS 54, 55 NASA ADS
• Olsen E.H., 1993, A&AS 102, 89 NASA ADS
• Philip A.G.D., Hayes D.S., 1984, PASP 96, 546 NASA ADS
• Taylor B.J., 1982, PASP 94, 663 NASA ADS
• Taylor B.J., 1984, ApJS 54, 259 NASA ADS