“…Based on text mining or entity extraction, the knowledge units are extracted to identify the discipline to which the knowledge units belong. Knowledge unit distribution (Xu et al, 2016;Wang et al, 2022), citation locations (Wang et al, 2021a, b) and coword network (Ba et al, 2019;Engerer, 2017) are used to characterize the diffusion, transfers and integration of knowledge among different disciplines and thus to reveal the interdisciplinarity of the research. Currently, knowledge units are mainly represented with terms, knowledge memes, keywords and topics contained in the publications (Wang et al, 2021a, b;Ba et al, 2019;Engerer, 2017;Li et al, 2021;Cheng et al, 2020;Mao et al, 2020), focusing on revealing the knowledge content in the research and expressing the details of knowledge interaction between different disciplines from a micro perspective.…”