1. Personal documents and certificates: there are personal documents or certificates of the deceased elderly, such as wills, letters, contracts, etc. Will be signed. You can find the signature by looking at these documents.

2. Relatives, friends and acquaintances: Ask relatives, acquaintances, colleagues or family members of the deceased elderly, and they will have the signatures of the elderly or know other sources where the signatures of the elderly are stored. Talk to these people and ask if you can provide relevant information.