+& \tiny Z. Liu et al. (2012)~\cite{ref135} & \OK & & \OK & & & & \OK & & \OK & & \OK & &\\
+
+& \tiny L. Zhang et al. (2013)~\cite{ref136} & \OK & & \OK & & & \OK & \OK & & \OK & & \OK & &\\
+
+& \tiny S. He et al. (2012)~\cite{ref137} & \OK & \OK & \OK & & & & \OK & & \OK & & & &\\
+
+& \tiny Y. Xu et al. (2001)~\cite{ref84} & \OK & & \OK & & & & \OK & & \OK & & & &\\
+
+& \tiny C. Vu et al. (2006)~\cite{ref132} & \OK & & \OK & & \OK & & \OK & & \OK & & \OK & &\\