(?P<strong>    \*\*
                               (?P<strong_text> (?:
                                   (?P>link) | (?P>em) | [^*] # Here
                               )+ )
                               \*\*
                ) |

                (?P<em>        \*
                               (?P<em_text> (?:
                                   (?P>link) | (?P>strong) | [^*] # Here
                               )+ )
                               \*
                )