MathJax Equation References

 Equations tags can be referenced using the \label{} and \ref{} or \eqref{} macros. For example, The famous equation (\ref{Einstein}) by Einstein, ... $E=mc^2\label{Einstein}\tag{1}$  produces The famous equation (\ref{Einstein}) by Einstein, ... $E=mc^2\label{Einstein}\tag{1}$