Contact the Ethiopian government direct. It's a quality operation. Google it. Or you'll have a quality embassy in Rome given the history between the two countries.

Christopher NOCK

WOLDEMARIAM, Writing both difference and similarity: towards a more unifying and adequate ortography for the newly written languages of Ethiopia: the case of Wolaitta, Gamo, Gowa and Dawuro, 2014.

Here are some materials on the topic:

Almaz W. G. 2016. “Norm Selection and Standardization in Gamo.” In Multilingual Ethiopia: Linguistic Challenges and Capacity Building Efforts, edited by Binyam Sisay Mendisu and Janne Bondi Johannessen, 273-293. Oslo Studies in Language 8(1).

Data D. 2006. “Enduring Issues in State-Society Relations in Ethiopia: A Case Study of the WoGaGoDa Conflict in Wolaita, Southern Ethiopia.” International Journal of Ethiopian Studies 2 (1/2): 141-159.

Hirut W. 2005. “The Orthography for Wolaitta, Gamo, Gofa and Dawuro: Problems and Recommendations.” Working Paper 1 (2), 186-206. Addis Ababa: Ethiopian Languages Research Center.

Hirut W. 2007. “The Challenges of Morther-tongue Education in Ethiopia. The Case of North Omo Area.” Language Matters 38 (2): 210-235.

Hirut W. 2013. “Revisiting Gamo: Linguists’ Classification Versus Self Identity of the Community.” International Journal of Sociology and Anthropology 5 (9): 373-380.

Hirut W. 2014. “Writing Both Difference and Similarity: Towards a More Unifying and Adequate Orthography for the Newly Written Languages of Ethiopia: The Case of Wolaitta, Gamo, Gofa and Dawuro.” Journal of Languages and Culture 5 (3): 44-53.

Hirut W. 2016. “Language Planning Challenged by Identity in a Multilingual Setting: The Case of Gamo.” In Multilingual Ethiopia: Linguistic Challenges and Capacity Building Efforts edited by Binyam Sisay Mendisu and Janne Bondi Johannessen, 295-318. Oslo Studies in Language 8(1).

I can provide copies of these materials if you are unable to locate them.