우주선.md

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 ## 참고자료
-1. [Lingenfelter, R. E., Canfield, E. H., & Hess, W. N. (1961). The lunar neutron flux. Lawrence Radiation Laboratory, University of California.](https://www.osti.gov/servlets/purl/4840348)
+1. [Litvak, M. L., et al. (2012). Global maps of lunar neutron fluxes from the LEND instrument. Journal of Geophysical Research: Planets, 117(E12), E00H22. https://doi.org/10.1029/2011JE003949](https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2011JE003949)
+2. [Lingenfelter, R. E., Canfield, E. H., & Hess, W. N. (1961). The lunar neutron flux. Lawrence Radiation Laboratory, University of California.](https://www.osti.gov/servlets/purl/4840348)
 
 
 ## γ-선