deletions | additions       diff --git a/bibliography/biblio.bib b/bibliography/biblio.bib  index fc35822..470d911 100644  --- a/bibliography/biblio.bib  +++ b/bibliography/biblio.bib 
...
adsurl = {http://adsabs.harvard.edu/abs/2010Sci...328..463O},  adsnote = {Provided by the SAO/NASA Astrophysics Data System}  }  @ARTICLE{2001AmJPh..69..970C,  author = {{Crouch}, C.~H. and {Mazur}, E.},  title = "{Peer Instruction: Ten years of experience and results}",  journal = {American Journal of Physics},  keywords = {Educational aids, Course design and evaluation, Research in physics education, General physics},  year = 2001,  month = sep,  volume = 69,  pages = {970-977},  doi = {10.1119/1.1374249},  adsurl = {http://adsabs.harvard.edu/abs/2001AmJPh..69..970C},  adsnote = {Provided by the SAO/NASA Astrophysics Data System}  }