@book{53660,
	author = {عمر حلمي},
	title = {معيار تمييز العقد الإداري /},
	publisher = {دار النهضة العربية,},
	year = {1993.},
	address = {القاهرة :},
	url = {https://fll.law.cu.edu.eg/fulltext/bks/B07-02175.pdf}
}