The phrase "a more lengthy" is correct and usable in written English.
It can be used when comparing the length of something to indicate that it is greater in length than another item or instance.
Example: "The report provided a more lengthy analysis of the data than the previous version."
Alternatives: "a longer" or "a more extensive".
We will also allow a more lengthy discussion than you will get in spring.
He can ask the union for a more lengthy explanation about the loans.
"I am doomed to be a more lengthy fragmentist," he said in a 2001 interview with Bomb".
Sharapova, on the other hand, required a more lengthy explanation, of her emergence and her operation and her comeback, all by the age of 25.
On Monday, News Corporation withdrew its intention to spin off BSkyB's 24-hour Sky News Channel, a move that automatically triggered a more lengthy regulatory review process.
Opponents of GM crops filed a lawsuit soon after and, in 2007, a federal judge ordered the USDA to conduct a more lengthy review.
Although forgiving someone (or ourselves) can happen in an instant, my experience is that it is usually a much more lengthy process requiring great patience, trust, persistence and prayer -- more like peeling an onion or a lotus blossoming than a lightning bolt.
Methods for in vivo testing of compounds for anti‐scrapie activity in transgenic mice, a much more lengthy and expensive process, are also discussed.
According to the authors (32) the SAM correlates highly with ratings obtained using a verbal, more lengthy, semantic differential scale.
You might not know how to end the conversation once it gets started and the other person goes into a much more lengthy and detailed story.
Stephen O'Connor, an executive from Morgan Stanley, came up with an even more lengthy estimate, saying his clients say it could take an entire day to renegotiate contracts and that could mean "100 man-years worth of effort".
