You are not restricted solely to America; you are allowed to bring in international examples. you must cite 7 sources but no more than 14 in proper APA STYLE. the thesis should be the last line on the introduction. as thesis I have " While marriage has declined and cohabitation has increased, cohabitation is not an alternative to marriage." 8 PAGES REFERENCES PAGE IS #9 you might want to go for cohabitation, or agaisnt it, it doesnt matter what you pick.