found: CIA world fact book online, Oct. 6, 2015:Madagascar (location: Southern Africa, island in the Indian Ocean, east of Mozambique; nationality: Malagasy (singular and plural), noun; Malagasy, adjective)
found: Merriam Webster online, Oct. 6, 2015:Madagascar (island W Indian Ocean off SE Africa; adjective or noun: Madagascan) Malagasy (a member of a people of Indonesian and African origin who inhabit Madagascar; plural: Malagasy or Malagasies)
found: Collins English dictionary online, Oct. 6, 2015:Madagascan (noun: a native or inhabitant of Madagascar) Malagasy ((plural) -gasy or -gasies a native or inhabitant of Madagascar)
found: National Geographic style manual, via WWW, July 13, 2015(Madagascan refers to the country of Madagascar. Malagasy refers to an ethnic group and its language: All residents of Madagascar are Madagascan, but not all are Malagasy)
found: Britannica online, Oct. 6, 2015:Madagascar (island country lying off the southeastern coast of Africa; Although located some 250 miles (400 km) from the African continent, Madagascar’s population is primarily related not to African peoples but rather to those of Indonesia, more than 3,000 miles (4,800 km) to the east; Malagasy peoples do not consider themselves to be Africans, but, because of the continuing bond with France that resulted from former colonial rule, the island developed political, economic, and cultural links with the French-speaking countries of western Africa; More than nine-tenths of the population is Malagasy, which is divided into about 20 ethnic groups; [does not use "Madagascan"])
found: Dugas, J.-Y. Dictionnaire universel des gentilés en français, 2006(Madagascar: Malgache, Malgache. Variant: Madécasse, Madécasse. In the 18th century, Malégache or Malegache and Madégasse were in usage)
found: Le petit Robert des noms propres, 2014(Madagascar: Malgaches)