Cataloguing tips - Recording authors in corporate body publication

Is it necessary to record a group of writers stated in a introductory page of a work published by government body?

That would depend on the prominence of the authors and how they are represented, and also on the content of the resource. If it says on the title page that the authors wrote the book, then we probably assert them as the creators, with the corporate body as 710. If they are just listed in the introduction , they may not need to be included. Remember that the corporate body is only asserted as creator, if they fit the RDA criteria for status as creator, so you may have situations when no one is listed as a main creator, but all are listed in 7XX fields.