# Biblatex citation is shown in the wrong way (same author used twice, first name appears) [duplicate]

I have a small problem with my citations.

When I use just one of the quotes below then the citation appears in the right way. But if I use both I always find the first name also in the citation.

Why is that and how can I avoid this?

Thank you very much :-)

\documentclass[a4paper,11pt,DIV=calc, titlepage]{scrartcl}

\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[ngerman]{babel}
\usepackage{filecontents}

\usepackage[babel, german=quotes]{csquotes}
\usepackage[style=authoryear-ibid,natbib=true, maxbibnames=9,maxcitenames=2,uniquelist=false, backend=biber]{biblatex}
\renewcommand*{\mkbibnamelast}[1]{\textsc{#1}}

\DefineBibliographyStrings{ngerman}{
}

\DeclareNameAlias{sortname}{last-first}
\DeclareNameAlias{default}{last-first}

\DeclareFieldFormat[article,inbook,incollection,inproceedings,patent,thesis,unpublished]{citetitle}{#1} %Anführungszeichen um Titel entfernen
\DeclareFieldFormat[article,inbook,incollection,inproceedings,patent,thesis,unpublished]{title}{#1} %Anführungszeichen um Titel entfernen

\begin{filecontents}{literatur.bib}

@Article{Lee1998,
Title                    = {PLANT RECOGNITION USING HARDWARE-BASED NEURAL NETWORK},
Author                   = {Won~Suk Lee and David~C. Slaughter},
Date                     = {1998-07-12/1998-07-16},
Year                     = {1998},

Institution              = {Department of Biological and Agricultural Engineering, University of California, Davis, USA},
Organization             = {Department of Biological and Agricultural Engineering, University of California, Davis, USA},
Owner                    = {Me},
Timestamp                = {2014.11.26},
Type                     = {Meeting Presentation}
}

@Article{Slaughter2008,
Title                    = {Autonomous robotic weed control systems: A review},
Author                   = {D.C. Slaughter and D.K. Giles and D. Downey},
Journaltitle             = {COMPUTERS AND ELECTRONICS IN AGRICULTURE},
Year                     = {2008},
Number                   = {61},
Pages                    = {63-78},

Owner                    = {Me},
Timestamp                = {2014.11.26}
}

\end{filecontents}

\begin{document}

Hallo1 \parencite{Lee1998} should look (Lee \& Slaughter, 1998) \\

Hallo2 \parencite{Slaughter2008} should look (Slaughter et al., 2008)

\printbibliography

\end{document}


## marked as duplicate by moewe, Jesse, user13907, Paul Gaborit, user31729 Dec 28 '14 at 9:28

• That is because biblatex does not know that "D.C. Slaughter" and "David~C. Slaughter" are the same person and it tries to distinguish between people with the same last name, so you can immediately tell which book is by Jane Smith and which was written by John Smith. You could go with uniquename=false as preamble option, but you should read up about uniquename either in the documentation or on this site (here or here). – moewe Nov 27 '14 at 5:46
• By the way: You should probably not use a non-breaking space in the .bib file. Just give the name as "David C. Slaugther" or better as "Slaugther, David C.", the same goes of course for Mr Lee. – moewe Nov 27 '14 at 5:48