Researches, virtual bibliographies: 

Current research about Latvian history, published in Historical articles in 2015 - “Roma Genocide in Latvia 1941-1944”, concludes that about 2000 Latvian Romas were killed during the Nazi occupation which is half of the Roma population of 1935 (3839 persons). As mentioned in the text, the real size of the Roma population in 1941 could be larger than official data, meaning that the number of victims could be larger than 2000 people.