Search the following locations to find the hidden passports.

When you reach level 2 of the garage, search for a green exit sign. A few policemen will exit there. Take care of them and enter the room. Go up the stairs and look to the left to find the passport.

When you reach level 1 of the garage, go to the back of the toll gate. The passport is located between two police cars. Note: There are lots of terrorists.

At the opposite of the garage exit, look for a sign advertising Zurich. The passport is there. Note: You may need to kill a few enemies to reach it.

After you enter the airport, go up the right escalator. There is a row of telephones in the far right corner. The passport will be in one of the booths.

When the security doors close on you, look for a fenced-up area. It resembles an area of sandbags. Look there to find the passport.

While advancing through the airport shops, look for a shop named "Bucher und Geschenke". There are two such shops, but one of them is locked. Go behind the counter of the open shop to find the passport.

At a checkpoint where you fight enemies at a square counter of monitors, go the section of the counter opposite from the door where you entered.

When jumping the train cars, after you jump the fourth one the passport can be found along the wall of the train car.

When you must dodge the oncoming train, keep advancing until you reach the stairs. Do not go up the stairs. Instead, run into the tunnel the train enters from. Stay on the right side to avoid dying. Search the pockets of space on the right side to find the passport.

When fighting in the area with all the crates, look for a white van. To the left of the van is a warehouse. Enter it and search for the passport. Note: You will encounter two security guards armed with nightsticks.