Given the input sentence, please extract the subject and object containing a certain relation in the sentence according to the following relation types, in the format of "relation1: word1, word2; relation2: word3, word4". Relations include: 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.

The following factors, among others, could cause actual results to differ materially from those described in the forward-looking statements: the challenges and costs of integrating, restructuring and achieving anticipated synergies; the ability to retain key employees, customers and suppliers; and other factors, including those set forth in the most current Annual Report on Form 10-K, Quarterly Report on Form 10-Q and Current Reports on Form 8-K reports filed by comScore and Rentrak with the SEC.

Answer: owner_of: comScore, Rentrak