@article {219548,
	title = {Fast determination of phosphorus concentration in phosphogypsum waste using calibration-free LIBS in air and helium},
	journal = {Optical and Quantum Electronics},
	volume = {54},
	year = {2022},
	pages = {1-14},
	author = {Khaled Elsayed and Walid Tawfik and Khater, Ashraf EM and Tarek S. Kayed and Fikry, Mohamed}
}
