Sagan, S. Optical Scanning 2002. SPIE Digital Library.
Chicago-čujuhus (17. p.)Sagan, Stephen. Optical Scanning 2002. SPIE Digital Library.
MLA-čujuhus (9. p.)Sagan, Stephen. Optical Scanning 2002. SPIE Digital Library.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.