This is the 3897th most frequent Polish word.
rosjanom
"Rosjanom" means "to Russians" or "for Russians" in English.
The dative case 'rosjanom' is used here indicating the recipients of the books.
Daliśmy książki Rosjanom.
We gave books to the Russians.
The dative case 'rosjanom' indicates the directed audience of the complaint.
Złożyli skargę Rosjanom na złe warunki.
They filed a complaint to the Russians about the bad conditions.
The dative case 'rosjanom' is used to show who benefited from the action of helping.