Don't allow <sup> to break line

HTML

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commoggdog consequat. Duis aute irure dolor in reprehenderi in voluptate vit eccccccccccccccccccccccccccccccsse cillum dolore eu fugiaggt nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim isasdsddddddddddddddd est laborum&nbsp;<a class="footnote" title="V. Umeljić, (2004.), U svijetu cvijeća i pčela: Atlas medonosnog bilja, Zagreb: Tisak" id="return-note-4832-1" href="#note-4832-1"><sup>[1]</sup></a>&nbsp;<a class="footnote" title="V. Umeljić, (2004.), U svijetu cvijeća i pčela: Atlas medonosnog bilja, Zagreb: Tisak" id="return-note-4832-1" href="#note-4832-1"><sup>[2]</sup></a>

CSS

left: -3px;
top: -0.5em;
font-size: 75%;
line-height: 0;
position: relative;
vertical-align: baseline;