deletions | additions       diff --git a/bibliography/biblio.bib b/bibliography/biblio.bib  index 51ebf02..463144e 100644  --- a/bibliography/biblio.bib  +++ b/bibliography/biblio.bib 
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month = {December},  year = {2015},  url = {http://physwiki.apps01.yorku.ca/index.php?title=Main_Page/PHYS_4210/Gamma_Ray_Spectroscopy&oldid=62207}  @article{article, @article{Hubbell2006,  author = {J.H. Hubbell},   title = {Electron–positron pair production by photons: A historical overview},  journal = {Radiation Physics and Chemistry},