1. �ndice de Atividade Econ�mica Regional do Rio Grande do Sul // Boletim Regional do Banco Central do Brasil;Banco Central do Brasil,2009
2. Indeksy intensivnosti vypuska tovarov i uslug po bazovym vidam jekonomicheskoj dejatel'nosti. Ezhemesjachnyj doklad. Janvar' 2000 -nojabr' 2011 [Indices of Basic Branches' Production;E F Baranov;HSE Monthly Report,2000
3. Consistent Economic Indexes for the 50 States // Review of;Theodore M Crone;Economics and Statistics,2005
4. Dating Cyclical Turning Points for Russia: Formal Methods and Informal Choices