@article {MenEtAl2007,
	title = {An Exact Approach to Direct Aperture Optimization in IMRT Treatment Planning},
	journal = {Physics in Medicine and Biology},
	volume = {52},
	number = {24},
	year = {2007},
	pages = {7333-7352},
	doi = {http://dx.doi.org/10.1088/0031-9155/52/24/009},
	author = {Chunhua Men and H. Edwin Romeijn and Z C Ta{\c s}k{\i}n and James F. Dempsey}
}
