Reference for Rosh Hashanah 68:3

ומי אמר רבי יוחנן הכי והאמר ר' יוחנן משום ר' שמעון בן יהוצדק בהלל ובמגילה אם שהה כדי לגמור את כולה חוזר לראש לא קשיא הא דידיה הא דרביה

one paused long enough to say the whole, he must go back to the beginning? - There is no contradiction: in one case he was giving his own opinion,in the other that of his teacher. But does not his own opinion [conflict with the above statement]? Was not R'Abbahu once following after R'Johanan reciting the shema',<span class="x" onmousemove="('comment',' V. Glos.');">³</span>

Jastrow