where can i find and "duplicate" some specific scientific books. My bib doesnt have them and im to poor to buy them atm thx to corona

I know about sci-hub but it has mostly articles (its realy fucking great tho)

To be precise im looking for (pls no bully)
management and psychology books, im an industrial engineering student.
Also would be nice if the site has access to literature from germany but thats not a must.