Below is the content of the official support article, followed by a guide on how to handle the transfer today.
If you are switching to a new computer, setting up a different browser, or simply moving your digital life to a new Google account, knowing how to is a vital skill. Manually copying links is tedious and prone to error, but Google Chrome provides several streamlined ways to move your entire library in seconds. transfer google bookmarks
If you are looking for a technical paper on the data migration, it does not exist because the service was sunsetted (decommissioned) rather than migrated. The data was not automatically transferred to a new system; users were required to manually export it before the deadline. Below is the content of the official support
There are also third-party extensions available that can help you transfer Google Bookmarks. One popular option is the "Bookmark Manager" extension for Google Chrome. If you are looking for a technical paper
If you are looking for the official documentation or "paper" (announcement) regarding this shutdown and how to transfer data, the primary source is the regarding the Bookmarks shutdown.