Prose
S. B. U. III. 3
In plain words
This one is not a verse or a piece of commentary at all — it is a small printed reference mark, 'S. B. U. III. 3,' most likely pointing a reader to chapter III, section 3 of the text. There is nothing here to translate; it is simply a citation left over from the page.
Close to the Sanskrit
This record contains no continuous Sanskrit sentence. It is a bare citation marker, 'S. B. U. III. 3' — almost certainly an abbreviated page or section cross-reference (chapter/part III, section or verse 3) carried over from the printed edition, with no independent content of its own to translate.