By Will Grant BBC News, La Tinta, Guatemala, Edited by - Vinuri Randhula Silva, IMAGE SOURCE, MIRRORPIX/GETTY IMAGES By Will Grant BBC News, La Tinta, Guatemala It is a fact that even many die-hard Abba fans do not know. Despite selling millions of copies over more than four decades, their massive 1979 hit, Chiquitita, doesn't earn the Swedish supergroup a penny. "We gave the copyright to Unicef," its composer and founding member of Abba, Bjorn Ulvaeus, told the BBC. "A lot of money has come in over the years because Chiquitita has been played and streamed a lot, and lots of records have been sold. So, I'm very happy about that." Written for Unicef's Year of the Child, Chiquitita - which means "Little Girl" in Spanish - was also the first song Abba recorded in Spanish, becoming a huge success across Latin America. From the start, Bjorn Ulvaeus says the band was clear about what they wanted the royalties to be used for. "I think that the ...