@conference {hamid1969ray,
	title = {A ray-optical approach to the analysis of microwave filters},
	booktitle = {Microwave Conference, 1969. 1st European},
	year = {1969},
	note = {n/a},
	pages = {189{\textendash}193},
	publisher = {IEEE},
	organization = {IEEE},
	abstract = {n/a},
	author = {Hamid, MAK and Kashyap, SC and Mohsen, A and Boerner, WM and Boulanger, RJ}
}
