“…In recent years, with the emergence and development of deep learning technologies, many approaches based on deep learning have been proposed [27,33,38,39,65,92,104], which greatly improves the accuracy and performance of cross-domain recommendation. To answer the question of how to transfer, a straightforward idea is to utilize overlapping entities, either users or items, to directly establish relationships between domains [23,40,77,85,92,109,111]. When there are no overlapping entities, some efforts are also made to establish linkages by extracting cluster-level patterns [50,71,84,90] or resorting to other auxiliary information (e.g., users' generated tags, reviews, user profiles, and item content) [30,83,96,98].…”