Spaces between superscripts dropped in join step
This may or may not be related to #44 (closed)
When superscripts are separated by regular spaces, in the join step, they are collapsed into one superscript and the separating spaces are dropped entirely. Example:
<p>...impact-related injury.<sup>6</sup> <sup>7</sup> <sup>8</sup> Then, there...</p>
<p>...linear impact-related injury.<sup>678</sup> Then, there...</p>
Instead, the non-superscript spaces should stay where they are.