Analysis of information sources in references of the Wikipedia article "Lotus E21" in English language version.
Allison admitted the team had run into difficulty with its Double DRS, which has appeared several times in practice but hasn't been raced yet [...] "We're going to take it away, have another think and most likely give it another go in the Abu Dhabi Young Drivers' Test where we'll have more time to develop it in a systematic fashion."
