\[
\begin{diagram}
\node[2]{\text{\bf Seok-Ku Ko}} \node{\text{\bf Zhou Jiuru}}\\
\node[2]{\text{\bf Xu Xingwang}} \arrow{ne} \arrow{e} \arrow{se} \node{\text{\bf Ngo Quoc Anh}} \\
\node[2]{\text{\bf Gerard Vinel}} \node{\text{\bf Li Si}} \\
\node[1]{\text{\bf William Abikoff}} \arrow{se} \arrow{sse} \arrow{ssse} \arrow{ne} \arrow{nne} \arrow{nnne} \node{\text{\bf Taiping Ye}} \\
\node[2]{\text{\bf Yan Jin}} \\
\node[2]{\text{\bf Yuanqian Li}} \\
\node[2]{\text{\bf David Pinchbeck}} \\
\end{diagram}
\]
