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L'apport des naturalistes bénévoles aux programmes de monitoring en Région wallonne ; The contribution of volunteer naturalists to monitoring programs in the Walloon Region
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A Synopsis of the Mutillidæ of the Belgian Congo
Bees of the Genus Megachile from the Belgian Congo
Parasitic Bees of the Genus Coelioxys from the Belgian Congo
Bees of the Genus Crocisa from the Belgian Congo and Notes on Trigona
Bees of the Genus Sphecodes from the Belgian Congo
Heriadine Bees from the Belgian Congo
African Bees of the Family Megachilidae (Gronoceras and Megachilidae) from Liberia and Belgian Congo
Heriadine and Related Bees from Liberia and the Belgian Congo (Hymenoptera, Apoidea)
African Bees of the Family Anthophoridae, Cheifly from the Belgian Congo and Liberia (Hymenoptera, Apoidea)