What does Q.B.V.D. stand for on the title page of a dissertation?

Question

I have seen Q.B.V.D. as the first line of titles pages of academic dissertations, like this one:

https://books.google.nl/books?id=YmpZAAAAcAAJ&pg=PA3&lpg=PA3&dq=Q.B.V.D&source=bl&ots=28TRv2QHOi&sig=vN4j7q4dHlyMtc_MCW2i-5SU038&hl=en&sa=X&redir_esc=y#v=onepage&q=Q.B.V.D&f=false

Does anyone have any idea what this stands for? I could fabricate guesses, but they would be completely arbitrary: none would be convincing at all.

Answer 1

It's also – more commonly, I believe – given as Q. D. B. V. = quod Deus bene vertat, 'May God cause this to turn out well'/'May God grant this success.'

This use of verto is under definition 18 in the Oxford Latin Dictionary:

18 (esp. w. advs.) To turn the course of (affairs) to a specificed (favourable, etc.) outcome.

Two example of dissertations that are headed by Q. D. B. V.:

• Example 1
• Example 2