PQSL right print order with php

I want to have the following struct on my print: (https://i.stack.imgur.com/e16ya.png)

My problem is that i want to all Nomos to be printed together for every Perifereia.

my code is:

$sql = pg_query($conn,"SELECT   Όνομα_Περιφέρειας,
Όνομα_Νομού,
Όνομα_Δήμου,
Γεωγραφικό_Μήκος,
Γεωγραφικό_Πλάτος
FROM Δήμοι
ORDER BY Όνομα_Περιφέρειας,Όνομα_Νομού,Όνομα_Δήμου ASC
");

while ($row = pg_fetch_row($sql)) {
echo "Περιφέρεια $row[0]";
echo ("\n");
echo "  Νομός $row[1]";
echo ("\n");
echo "      Δήμος $row[2]: $row[3],$row[4]";
echo ("\n");
}

now my result is (https://i.stack.imgur.com/Avunw.png)