1947 – 1949    Intermittent study on the Central African collections at the Musée royal de l’Afrique centrale, Tervuren.

1949 – 1961   Ethnographic collecting during field research. The collections are at: the Musée royal de l’Afrique centrale, Tervuren; the Schoolmuseum of the City of Ghent (Belgium); the Institut pour la Recherche scientifique en Afrique centrale (Lwiro, Congo) and several small museums I created in Congo, one at the IRSAC research center of Lwiro (near Bukavu, Kivu) and one at the University of Lovanium (now National University) in Kinshasa.

• The Tervuren collections comprise the great art collections from the Bwami association of the Lega and Bembe, the Basikasingo sculptures, and Bahoma and Baciba (along Lake Tanganyika) figurines, and the Nyanga “material” objects transferred from the Schoolmuseum at Gent.
• The IRSAC collection at the Lwiro research center, funded by IRSAC, included a comprehensive overview of Nyanga material culture (790 pieces were exhibited mainly from the Ihana, Kisimba, and Ikobo political divisions). They illustrated housing, fire-making, food preparation, utensils, tools, pottery, dress and body ornaments, fish traps, hunting equipment, cult objects, circumcision rites, musical instruments, games, etc. (See Folia Scientifica Africae Centralis, June 1956, p.15). The collection also included objects from the following people: Havu, Kuba, Komo, Lendu, Logo-Dongo, Nande, Ruwenzori area, Tembo.
• The Lovanium collection set up between 1958 and 1961 included around 2516 objects, funded by Lovanium University. This collection was essentially made during my ethnographic surveys between 1957 and 1958 among the:
  • Agbarambo
  • Aluur
  • Bamanga
  • Bari
  • Bira (forest)
  • Bwa
  • Cokwe
  • Leka
  • Lese
  • Lokele
  • Malele
  • Mamvu
  • Mayogo
  • Mbuba
  • Meegye
  • Mongelima
  • Mongo (Ekota and Bakucu)
  • Pende
  • Salampasu
  • Shi
  • Suku
  • Talinga
  • Zande
  • Yeka
  • Yew

A number objects in the display had been acquired through the good offices of a few missionnairies, colonial administrators, and researchers; they included objects from such groups as the: Kongo, Lokele, Lunda, Mongo, Suku, Tetela

1963 Consultation work for the new Museum and Laboratories of Ethnic Arts and Technology (now Fowler Museum at University of California of Los Angeles).

1965 Consultation work for the Smithsonian Insitution, Washington DC: reports on the Lega collection by E. Burk.

1965 – 1966 First Curator of African collections at the newly created Laboratory of Ethnic Arts and Technology (UCLA), charged with cataloguing and ethnographically validating a number of new collections, including the large and diversified ethnographical and art collections of Hallet and the Sir Henri Wellcome Trust.

1971 – now Intermittent research in various ethnographic, natural history and art museums in the United States and in European countries (before 1989, part of this research was sponsored by the Social Science Council, the S Kress Foundation, the Rockefeller Foundation, the National Endowment for the Humanities, Washington, DC; two different grants, the Guggenheim Foundation, the Universities of Delaware, Southern Florida, California, and Yale). The research included European ethnographic museums in Brussels, Antwerp, Louvain, Leiden, Rotterdam, Berg-en-Dal, Amsterdam, Hamburg, Bremen, Stuttgart, Frankfurt, Freiburg-am-Breisgau, Cologne, Berlin, Munich, Ulm, Vienna, Paris, Geneva, Lausanne, Zürich, Copenhagen, Göteborg, Stockholm, London.