Entity and schema alignment between the knowledge graphs may be further necessary to better integrate (parts of) external knowledge graphs, using linking tools for graphsexternal identifiers [Pellissier Tanon et al., 2016], or indeed may be done manually [Pellissier Tanon et al., 2016].
In the LaTeX source, there is:
Entity and schema alignment between the knowledge graphs may be further necessary to better integrate (parts of) external knowledge graphs, using linking tools for graphs~\cite{silk,NgomoA11}, external identifiers~\cite{pellissier2016freebase}, or indeed may be done manually~\cite{pellissier2016freebase}.
The PHP should be updated by changing graphsexternal identifiers into graphs <?php $references->cite("silk","NgomoA11"); ?>.
There is this sentence in Section 6.4.3:
In the LaTeX source, there is:
The PHP should be updated by changing
graphsexternal identifiersintographs <?php $references->cite("silk","NgomoA11"); ?>.