This is a valid technical request, but "paper" can mean different things (a research paper, a procurement note, or a simple cheat sheet).
6.5.0 Update 3 (Build 19193954) – final release. Step 4: Verification (SHA256 Checksum) After download, verify integrity: esxi 6.5 download iso
Compare output to the checksum listed on the download page. Warning: Only for lab environments. Not official. This is a valid technical request, but "paper"
Since you likely need a (for IT procurement, a lab setup guide, or an assignment), I have prepared a Technical Brief & Download Guide for VMware ESXi 6.5. This is a valid technical request
Older builds are sometimes mirrored on tech archive sites (e.g., archive.org). Example URL structure (now defunct for direct access): https://download3.vmware.com/software/vmw/esx/... (No longer public).
Which format do you actually need?