UseHashesToCitePapers

recently i saw some somebody*)
posting a link to a 
scientific paper**)
wrt CoronaVirus/NcOv

when trying to
download this paper *twice* via curl
i saw that it changed it's sha256sum!

so now i collect
dois with their corresponding
sha256sum of a version that
i store on my HardDisk

examplea:
MiPa2848
2848fd1827d08b44dafb92f2779d7f123fa7ea21a3ede79eb416e54028a70606
doi:10.1101/2021.01.18.427166

MiPac8e5
c8e5c49eda0f71b649714355984c79fdb9371dfb87e2d611737c16b6ac362ba9
doi:10.1038/s41586-020-2008-3


isnt this astonishing?
after decades
if not
centuries
of scientific publishing

no simple mechanism
has emerged
to identify
the most fundamental
unit of scientific activity itself:
the paper!
(which is - of course- no
longer printed on dead wood
but only a sequence of bits)

fun fact:
you cant quote your on paper

ps:
f*ck ElseVier & co

*) SoBo
**) MiPa2848