A. Farid and S. Hranilovic, “Capacity bounds for wireless optical intensity channels with gaussian noise,ˮ Information Theory, IEEE Transactions on, vol. 56, no. 12, pp. 6066-6077, December 2010.
 A. Farid and S. Hranilovic, “Upper and lower bounds on the capacity of wireless optical intensity channels,ˮ Nice, ISIT2007, France, pp. 2416-2420, June 2007.
 J. G. Smith, “The information capacity of amplitude and variance constrained scalar gaussian channels,ˮ Information and Control, vol. 18, no. 3, pp. 203-219, 1971.
 S. Shamai, “Capacity of a pulse amplitude modulated direct detection photon channel,ˮ in Proc. IEE Communication, Speech, and Vision, vol. 137, pp. 424-430, December 1990.
 A. Farid and S. Hranilovic, “Capacity of optical intensity channels with peak and average power constraints,ˮ IEEE ICC, IEEE Communications Society Subject Matter Experts.
 A. Farid and S. Hranilovic, “Channel capacity and non-uniform signaling for free-space optical intensity channels,ˮ Selected Areas in Communications, IEEE Journal on,vol. 27, no. 9, pp. 1553-1563, December 2009.
 A. Garcia-Zambrana, C. Castillo-Vazquez and B. Castillo-Vazquez, “On the capacity of FSO links gamma-gamma atmospheric turbulence channels using OOK signaling,ˮ Wireless Communications and Networking, EURASIP Journal on, vol. 2010, pp. 1-9, March 2010.
 A. Rezazadeh and G. A. Hodtani, “A general upper bound for the capacity of free space optical channel and the corresponding optimal input distribution,ˮ Australian Communications Theory, Workshop, pp. 34-39, 2012.
 S. M. Moser, “Duality-based bounds on channel capacity,ˮ Ph.D. dissertation, Swiss Fedral Institute of Technology, 2005.
 A. Lapidoth, S. M. Moser, and M. A. Wigger, “On the capacity of free space optical intensity channels,ˮ in Proc. Information Theory, IEEE Int. Symp., pp. 2419-2423, 2008.