Ask HN: Books on Selling $1M Software Services Contracts

Patio11 has written extensively about selling oneself as a software consultant. (That is, a solopreneur soliciting contract work.)

However, there's a process for selling the services of a larger development team to firms with budget for $1+ million software services needs.

(For example, $1 million to have six people build an app and backend.)

What would you recommend as the best books to learn the latter?

That is, books that explain how to sell "contract software development" to organizations with sufficient budget?

I'm asking for a friend. Not joking. :)