CITROEN DS3 Handbook page 182

Child seats recommended by CITROËN
CITROËN offers a range of recommended child seats which are secured using a three point seat belt.
From 22 kg (approximately 6 years), the booster is used on its own.
Group 0+: from birth to 13 kg
L1
"RÖMER baby-Safe Plus"
Installed in the rearward facing position.
Groups 2 and 3: from 15 to 36 kg
L4
"KLIPPAN Optima"
L5
"RÖMER kIDFIX"
Can be fitted to the vehicle's ISOFIX mountings.
The child is restrained by the seat belt.