Question

Three promotional materials used by public relations include:

Answer 1

Three promotional materials used by public relations include pamphlets, books and articles. 
The science of building relationships between an organization and its main audiences is called public relations. This branch may sometimes use promotional materials to reach their audience to promote their products and services. 

Answer 2

Hi,

Three promotional materials used by public relations include:
- pamphlets, - books,
- articles