jstyle sheet, APA6 citation style for LibreOffice with JabRef. This code works in conjunction with the existing programs JabRef: https://github.com/JabRef/jabref and LibreOffice.
To use, download the .jstyle sheet. Then, connect JabRef to LibreOffice. When connected, click "Select Style" in the LibreOffice citation menu on the left of the JabRef programme. Then click '+' and add the downloaded .jstyle file from here.
Caveat: this code is not perfect. Though I believe I have done a pretty good job, be sure to check your References list and edit any weird things before creating your final document. Everytime you click the 'refresh' button in JabRef, it will change any manual changes you make in the References in the LibreOffice document. One way to get around this is to change things in JabRef itself and/or the .jstyle sheet. Another, perhaps easier way is to quickly go through the references in LibreOffice and edit them before saving the final document as a PDF. Then your manual changes will stay the way they are.