Every person, or agent or officer thereof, employing minors, either directly or indirectly through third persons, shall keep on file all permits and certificates, either to work or to employ, issued under this chapter or Part 27 (commencing with Section 48000) of the Education Code. The files shall be open at all times to the inspection of the school attendance and probation officers, the State Board of Education, and the officers of the Division of Labor Standards Enforcement.