Seok Choe, M. et al. 2018. Study on the Increase in the Penetration Power in Accordance With the Changes in the Nozzle Hole of CNG High Pressure Injector. International Journal of Engineering & Technology. 7, 2.33 (Jun. 2018), 118–1172. DOI:https://doi.org/10.14419/ijet.v7i2.33.18009.