[js8]

I can't make any recommendations (because it's anecdotal) but I did have some good experience with biphasic sleep when studying mathematics for the university exams. Roughly the schedule was:

- Wake up at around 9 am, study till around 3 pm.

- Sleep till around 7 pm.

- Study some more, till 2-3 am.

- Sleep again.

I think there is something about the sleep that organizes your thoughts and therefore it might very beneficial to sleep more often (but not necessarily less) if you are either learning something very quickly or trying to solve a difficult mental problem.