@STRING{ nice_journal = "Nice Journal" }
@STRING ( jean={Jean} )
@STRING{cesar = {César}}

@ARTICLE{Cesar2013,
  author = jean # " " # cesar,
  title = {An amazing title},
  year = {2013},
  month = jan,
  volume = {12},
  pages = {12-23},
  journal = nice_journal,
  comments = {A comment},
  keyword = {keyword1, keyword2},
}