The first search on WoS followed five steps. 1. We selected the database for documentary analysis (Web of Science Core Collection).2. We set up a basic search ("BLOCKCHAIN" or "BLOCK CHAINS" or “BLOCK CHAIN” or "BLOCK-CHAIN" or “BLOCK-CHAINS” or "BLOCKCHAINS" or "CHAIN OF BLOCKS" [TOPIC]. All keywords were enclosed in quotation marks to ensure that they were not split during the retrieval process, except for "BLOCKCHAIN" and “BLOCKCHAINS”).3. We cut the search time to 2020 without setting the start time.4. We chose the relevant citation indexes (“SCI-EXPANDED” and “SSCI” and “A&HCI”).5. We limited the file type to "ARTICLE" and the language to "ENGLISH."
A total of 3589 publications were retrieved. To optimize the search results, we manually screened the literature identified by WoS according to INCLUSION AND EXCLUSION CRITERIA.After the second search, we obtained 2993 publications used to analyze the blockchain's scientific evolution. INCLUSION AND EXCLUSION CRITERIA 1、Inclusion Criteria Rationale for Inclusion Papers directly or indirectly discussing blockchain (e.g., smart contacts and PoW)To conduct a systematic review, it was vital to review articles focused not only on blockchain but also on the characteristics of the blockchain (e.g., consensus mechanism and distributed ledger)2、Exclusion Criteria Rationale for Exclusion Papers not related to blockchainOnly direct research on blockchain technology, its unique functions, and its applications are relevant to this research.Otherwise, it will be considered irrelevant to the blockchain. (e.g., blocks on the chemical chain)Papers appear many times.Only one record is kept for duplicate articles.