I am conducting a scoping review and am wondering about a particular source of gray literature. An NGO produces a report that is relevant to my topic every two years. Two of them appeared in my origional search (but not the most recent). Should I include a) every report available from the NGO b)only the two that appeared in my search c) only the most recent one, which was not part of my origional search or d) something else? I am using the JBI method. Thank you!