What is the relationship between publishing and publication in the context of the input sentence. Choose an answer from: product/material produced; manufacturer; distributed by; industry; position held; original broadcaster; owned by; founded by; distribution format; headquarters location; stock exchange; currency; parent organization; chief executive officer; director/manager; owner of; operator; member of; employer; chairperson; platform; subsidiary; legal form; publisher; developer; brand; business division; location of formation; creator.

Magazine publishing revenues declined 35% mainly due of course to the COVID-19 situation which led to fewer issues of some title and also to the discontinuation of the publication of Elle Canada and Elle Québec magazine.
product_or_material_produced