1. http://adsabs.harvard.edu/abs/2014SPIE.9143E..1IN.
2. http://adsabs.harvard.edu/abs/2014SPIE.9143E..49S.
3. http://adsabs.harvard.edu/abs/2012SPIE.8442E..3UM.
4. http://adsabs.harvard.edu/abs/2014SPIE.9143E..1KR.
5. http://adsabs.harvard.edu/abs/2012SPIE.8442E..0PB.