Bureau of Industrial Service. During the 1950s and 1960s, networks, studios and program sponsors often distributed publicty material through an ad or publicity agency. The "Bureau" was used by all of them at times during this period and was used quite extensively during this time. It was a division of ad agency Young & Rubicam.
Note that it may still be copyrighted in jurisdictions that do not apply the rule of the shorter term for US works (depending on the date of the author's death), such as Canada (50 p.m.a.), Mainland China (50 p.m.a., not Hong Kong or Macao), Germany (70 p.m.a.), Mexico (100 p.m.a.), Switzerland (70 p.m.a.), and other countries with individual treaties.