Retrieved 2009-06-06. ↑ Petrovsky, Gury T.; Tolstoy, Michael N.; Lubarsky, Sergey V.; Khimitch, Yuri P.; Robb, Paul N.; Tolstoy; Lubarsky; Khimitch; Robb (1994). Stepp, Larry M., ed. "2.7-meter-diameter silicon carbide primary mirror for the SOFIA telescope".