Expanding the gender gap in sales begins in the language sales training is taught. A primary source of sales techniques comes to mind:

How to Win Friends and Influence People by Dale Carnegie.

Businesswoman Woman Power from Pixabay

Components of this tome are in books like Fanatical Prospecting, Gap Selling, and SPIN Selling.

Is it meant for all salespeople?

Is it meant for women? I don’t recall one reference to a female salesperson in the book.