The command used by fzf for listing citations was not working anymore
because the command used in fzf is launching an interactive selector.
Therefore , the --all option have been added in order to mitigate the
issue.
This is a dirty workaround
If you select multiple papers at once, they are put in the same cite
bracket (comma separated). "/" is substituted out of the id. Since this
also happens for the bibtex refs.