The part of a sentence 'have only been found' is correct and usable in written English.
You can use it when emphasizing that something has been discovered recently. Example: Remnants of ancient civilizations have only been found in the last few centuries.
Contours of such a joint governance process have only been found in the Rotterdam case.
Given to retiring good leaders, suitable candidates have only been found in two of the last six years.
Historically, energy-harvesting technologies have only been found in niche markets, powering wireless sensors and RFID tags in particular.
To date, these variants have only been found in individuals with either LOAD11 or EOAD (this study).
These structures have only been found in primate and other large mammals, but not in mouse photoreceptor cells17.
Aetosaurs have only been found in sediments of the Late Triassic, when all the land of the world was joined together in the supercontinent Pangea.
Aetosaurs have only been found in sediments of the Upper Triassic, when all the land of the world was joined together in the supercontinent Pangea.
Notably, we identified sequences that are most closely related to the sigma class enzymes which so far have only been found in animals.
Petroleum plays have only been found in the Sangonghe Formation (J1s) located on structural ridges that consist of sand bodies comprising these sequences.
Feathered dinosaurs have only been found in a small area of China, but Barrett believes the discovery confirms that feathers were common in dinosaur evolution.
After receiving his results, he wrote: "Several species I've got, such as Marimonas, have only been found in the ocean before.
