Sun, D., Li, S., Yan, W., Jiao, F. and Chen, J. 2020. Research on User Interest Expression and Recommendation Service based on Three-dimensional Relationship of Users and Items. International Journal on Recent and Innovation Trends in Computing and Communication. 8, 5 (May 2020), 01–15. DOI:https://doi.org/10.17762/ijritcc.v8i5.5382.