SIMBAD references

The nebula was independently noted and reported by K. B. Quattrocchi (Clovis, CA, U.S.A.) and M. Helm (Fresno, CA, U.S.A.), who originally found it on eight separate 10-min images taken on 2008 July 17.75 with a 40.6-cm f/3.75 astrograph (+ FLI Microline 16803 CCD camera + H-alpha filter) located at the Sierra Remote Observatories in the Sierra Nevada Mountains, providing the position end figures of the nebula as 21s.5, 43"; they have posted photographs and other information on this nebula at website URL http://www.lostvalleyobservatory.com/page29crescentbubblenb/.