Following typical conventions, bibliographical information missing from the publication, but which can be reliably recovered, should be printed between square brackets []. When this applies to the name of the author, this is printed somewhat awkwardly both in the citations and in the bibliography. In the example below, I would like the citations to appear as
([Lennon 1970]; Lennon 1972)
and the references to appear as
[Lennon, John] ([1970]). [Peace on earth]. [London].
Lennon, John (1972). More peace on earth. London.
\documentclass{article}
\usepackage{csquotes,filecontents}
\usepackage[style=authoryear,dashed=false]{biblatex}
\begin{filecontents}{\jobname.bib}
@BOOK{lennon1970,
AUTHOR = "[John Lennon]",
TITLE = "[Peace on earth]",
YEAR = "[1970]",
LOCATION = "[London]"}
@BOOK{lennon1972,
AUTHOR = "John Lennon",
TITLE = "More peace on earth",
YEAR = "1972",
LOCATION = "London"}
\end{filecontents}
\addbibresource{\jobname.bib}
\begin{document}
\parencites{lennon1970}{lennon1972}.
\printbibliography
\end{document}


{McCartney, Paul and [Lennon, John]}? – Audrey Mar 07 '13 at 01:08