Such Levallois cores were found during the first half of the 20th century near Thebes and Abydos. Scientific interest in these artefacts began very early during the 1860ies (http://www.aggsbach.de/2012/12/thebes/.). Among the early researchers of the Paleolithic in Egypt, C.G. Seligman made the most valuable contributions.
Charles Gabriel Seligman (1873 –1940) was a British physician and ethnologist. His main ethnographic work described the culture of the Vedda people of Sri Lanka and the Shilluk people of the Sudan. He was a Professor at London School of Economics and was highly influential as the teacher of such notable anthropologists as Bronisław Malinowski, E. E. Evans-Pritchard and Meyer Fortes all of whose work overshadowed his own (http://history.prm.ox.ac.uk/collector_seligman.html).
Seligman visited Egypt twice in the early 20th century, collecting extensively each time, especially in the areas around Abydos and Thebes. Particularly valuable are significant field observation passages from his diaries. At Abydos, for example, Seligman noted discolored circles on the desert surface and interpreted them as remnants of Paleolithic huts. While this interpretation is likely erroneous, similar discolorations still intrigue researchers today and the problem of their interpretation is far from being resolved. Stone circles of unknown age were later also reported from the Maghrebinian Sahara and have been interpreted as the remains of Acheulian huts by some investigators.
We should stay open minded and not easily dismiss the idea of a long visibility and longevity of artificial structures in desert areas, as recently demonstrated by Archaeologists working in the Negev desert. They uncovered a 5,000-year-old leopard trap alongside one that is estimated to be 1,600 years old. These traps were and are used by herders to keep their flocks safe from predators. Such traps are still built in Yemen and therefore the tradition of these buildings is at least 7000 years old.
Historical records from the Near east, based on eyewitness accounts, attest that Bedouins used long stone walls, known as desert kites, which ranged for up to tens of kilometers, for witch hunt and mass slaughter of migrating gazelle herds in the 19th and early 20th centuries. Recent excavations in Syria showed, that this hunting strategy was already established 5000 years ago at Tell Kuran.
Seligman not only conducted, but also published, the first thorough investigations of Egyptian prehistory. In one of his contributions he reaches the conclusion that there is no correlation between archaeological industries from particular periods and Nile terraces, an insight well ahead of his time and still valid today. Another contribution was the observation, that the “paleolithic patina” was similar on implements from the ESA, MSA and LSA and the conclusion that patina could not be used for an age determination of artifacts.
A very important issue is Seligman’s first description of the operational sequence of the Nubian core method, long before the reports of the Combined Prehistoric Expedition in the 1960ies. Seligman already used a diacritic approach, as demonstrated by one of his illustrations from the 1921 book: “The Older Palaeolithic Age in Egypt”.