A multi-value 3D crossbar array nonvolatile memory based on pure memristorsJingru Sun, Kexin Kang, Yichuang Sun, Qinghui Hong and Chunhua WangEur. Phys. J. Spec. Top., 231 16-17 (2022) 3119-3130DOI: https://doi.org/10.1140/epjs/s11734-022-00576-9