Influencing on decision making is a essential skill to any business professional. It applies to both business-to-business context as well as your business environment context. In reference to the second item, you need at least to understand how a business environment impacting political decision making process works. The Brexit negotiation process (or processes?) is a typical example of such an issue. Because the European Easter holidays are about to start the reading tip of the day gives you two books in influencing in one go:
Enjoy your time with these two in many ways different manuals of influencing.