Which preposition to use with cerny

in Occurrences 1%

"The following letter, which refers to the fighting on the Aisne and was found on a German officer of the Seventh Reserve Corps, has been printed and circulated to the troops: "'Cerny, South of Paris, Sept 17.My Dear Parents:Our corps has the task of holding the heights south of Cerny in all circumstances till the Fourteenth Corps on our left flank can grip the enemy's flank.

Which preposition to use with  cerny