Any of the apprenticeship schemes recognized herein may be undertaken or sponsored by a single employer or firm or by a group or association thereof or by a civic organization. Actual training of apprentices may be undertaken:
(a) In the premises of the sponsoring employer in the case of individual apprenticeship programs;
(b) In the premises of one or several designated firms in the case of programs sponsored by a group or association of employers or by a civic organization; or
(c) In a Department of Labor and Employment training center or other public training institution.