Back up or restore data on your Android device
https://support.google.com/android/answer/2819582?hl=en

https://www.heise.de/tipps-tricks/Android-Backup-So-gelingt-die-Datensicherung-3900932.html?hg=2&hgi=0&hgf=false

https://www.freenet-mobilfunk.de/digitalrepublic/tipps/android-backup

https://www.experte.de/datensicherung/android-backup