Hi,
I've been queried by HR to present "Letter of Reference from previous employers". Since, i am not used to this, i don't know exactly what exactly they want from me. Previously, I've worked for companies in a country where such kind of papers doesn't exist.
Any idea/help would be very appreciated.
Thanks,

Perhaps you can ask your previous manager to write you a reference letter, in which they describe you as an employee. It is quite common in Switzerland to have these documents, at least, that is what I have noticed up until now.