Retrieved 2018-04-18. ↑ "NED Query Results for NGC 4876". ned.ipac.caltech.edu. Retrieved 2018-04-19. ↑ "Revised NGC Data for NGC 4876". spider.seds.org. Retrieved 2018-04-18. ↑ "New General Catalog Objects: NGC 4850 - 4899". cseligman.com.