The once familiar APA 6th style has been replaced, as of 2020, with a 7th edition. The new style manual includes some significant changes to formatting papers and has attempted to make language more inclusive and bias free. Among some of the new changes:
The cheat sheet from Purdue now reflects APA 7 but the Harvard guide still refers to APA 6. Also take a look at:
Also helpful may be the following manuals which are available as ebooks:
Go to http://www.zotero.org
Pro-tip: Use Zotero Standalone which means you have to download the software to your computer.