"northern border of Mongolia" . "Mongolia\u2013Russia" . . "Mongolian border" . . "Russia-Mongolia border-crossing" . "Russia-Mongolia border" . "the north" . . "Mongolia\u2013Russia_border#Tripoints" . "Mongolia\u2013Russia border" . "to the north" . "land border with Mongolia" . "Russia's border with Mongolia" . "Mongolia\u2013Russia border" . . . "border with Mongolia" .