No 1 will study more than a few, and recruiters tell me that if they want to know other people's opinions of an applicant, they'll ask for formal references. http://uk-kod.ru/2018/02/19/%d0%b7%d0%b0%d1%81%d0%b5%d0%b4%d0%b0%d0%bd%d0%b8%d0%b5-%d0%ba%d0%be%d0%bc%d0%b8%d1%81%d1%81%d0%b8%d0%b8-%d1%83%d1%84%d0%b0%d1%81/