Be careful with fluege.de. I tried to book a flight 3 months in advance (Moscow-Stuttgart). The process took something like 10 minutes - personal information, card details etc. Everything was OK till I pressed 'booking' button. After about a minute of 'search machine working', a message came 'no relevant flights, sorry'. Something suprising, but OK. I tried another portal and bought a similar ticket. Then came a real suprise: a confirmation from fluege.de that my flight is booked! I tried to cancel the reservation, but it cost me 100 euro! Nice service. Never again.