Mid Air Collisions

One of the books of Philip Wills has a chapter that describes how the BGA
was able
to obtain the freedom to fly gliders in controlled airspace in the UK. As
I recall, this
was the result of a statistical analysis on the probabilities of mid air
collisions. Would
anybody know where I may be able to lay my hands on this report or anybody

provide it or perhaps a copy of the chapter of the book.

It has been many years since my reading the book to which I no longer have
access.
I am an inactive glider pilot in Bangalore India that has airport problems
which
however are not related to gliders . The way the BGA tackled their problem
so many
years ago may have relevance hence my request.

I am also making this request to the BGA.

Thanks,

Sukumar