Final answer:
The necessary actions in case of an emergency with DGR in the cabin are found in the cabin crew quick reference manual, which provides immediate guidance for various emergencies.
Step-by-step explanation:
In case of an emergency with Dangerous Goods Regulations (DGR) in the cabin, the necessary actions are typically found in the "cabin crew quick reference" manual. This manual is designed to provide immediate guidance and is usually accessible during a flight. The cabin crew quick reference manual contains specific procedures for a range of emergencies, including those involving dangerous goods, to ensure the safety and security of everyone on board.