Few references to explore:

1. Research Papers:

- "Simultaneous Wireless Information and Power Transfer in Modern Communication Systems" by D. W. K. Ng et al. (2017)

- "Intelligent Reflecting Surface-Aided Wireless Communications: A Tutorial" by Q. Wu et al. (2019)

- "Intelligent Reflecting Surface-Aided Wireless Communications: Joint Active and Passive Beamforming Design" by Q. Wu et al. (2019)

2. Books:

- "Wireless Information and Power Transfer: A New Paradigm for Green Communications" by D. W. K. Ng et al.

- "Intelligent Reflecting Surface in Wireless Communication: Theory, Design, and Applications" by Q. Wu et al.

3. Online Courses and Tutorials:

- "Wireless Communications for Everybody" (Coursera) – This course covers various wireless communication topics, including SWIPT.

- "Wireless Power Transfer" (Coursera) – This course focuses specifically on wireless power transfer techniques, including SWIPT.

4. IEEE Xplore:

IEEE Xplore is a digital library that contains a wide range of research papers and articles on wireless communication and related topics. You can search for specific papers related to SWIPT and IRS.

5. Conferences and Journals:

- IEEE Transactions on Wireless Communications

- IEEE Transactions on Communications

- IEEE International Conference on Communications (ICC)

- IEEE Global Communications Conference (GLOBECOM)

- IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP)

Hope it helps