Update introduction.tex

AAAI2021/tex/introduction.tex

@@ -3,8 +3,8 @@
 
 The emergence of language has always been an important issue,
 which attracts attention from a broad range of communities,
-including philology~\cite{partee2008compositionality}, biology~\cite{}, and computer
-science~\cite{}. Especially in computer science, efforts in recent years trying to explore
+including philology, biology, and computer
+science. Especially in computer science, efforts in recent years trying to explore
 the emergent language in virtual multi-agent environments, where
 agents are trained to communicate with neural-network-based methods such as deep
 reinforcement learning~\cite{kottur-etal-2017-natural,bogin2018emergence,lazaridou2018emergence,choi2018compositional,jaques2019social,mul2019mastering,kharitonov2019egg,labash2020perspective,chaabouni2020compositionality}.