AnyStyle.io: this tool allows you to copy and paste your references (note: each reference must be on a single line), parse and convert them into a format that can then be imported into Zotero. Select the BibTeX format. The file will automatically open in Zotero, or you can open the File -> Import menu and select the file (with a .bib extension). The references will be placed in a special anystyle collection. Do not forget to check the references and make some corrections if necessary. It is recommended to divide the references to be imported into groups of maximum 10 references.