"further learned" is a correct and usable phrase in written English.
It can be used when additional information is being presented or discussed on the same topic. For example, "Through this course, I further learned the importance of accurate record-keeping."
Retailers have further learned to mix up the deals they offer online or in the stores to allow them to get traffic through both.
The high-bandwidth network, she further learned, will transmit data at rates above one gigabit per second, improving performance tenfold over current wireless networks.
The agency further learned that the arrangement approved by the development officials included language that made it appear as if investigation officials had, in fact, been aware of the arrangement.
The Guardian has further learned that the 27 member states have sought a legal opinion from the European commission on a possible extension of the two years allowed for talks under article 50 of the Lisbon treaty.
Harris and Betty and the rest of the table further learned about the hour John had just spent walking through Times Square, looking for the neon sign of the kitten with the spool of thread, which he'd seen pictures of but guessed must now be gone.
Mel further learned that 30 -50% of New Orleans inner-city children had lead poisoning even before the storm.
But Burnquist took switch-stance further, learning a full repertory of tricks.
We also produced a whole suite of baby first aid advice videos to inspire further learning.
Provides details of their characteristics and physical features, and suggests activities for further learning.
We further learn in Mitchell's novel that the unmarried Rhett may have a son in New Orleans.
However, loans for learners who are already employed are not an appropriate way to fund further learning.
