Michael, M. 2021. The Relationship Between Knowledge and Perception of Patient Delivery Nurses About The Hazards of X-Ray Radiation In The Radiology Installation of The University Of North Sumatera Hospital. International Journal of Economic, Technology and Social Sciences (Injects). 2, 2 (Oct. 2021), 661–666. DOI:https://doi.org/10.53695/injects.v2i2.1075.