Search for: [Subject and Keywords = czasopisma 20 w.] OR [Subject and Keywords = eksploatacja] OR [Subject and Keywords = gazy] OR [Subject and Keywords = odwierty] OR [Subject and Keywords = produkcja i handel] OR [Subject and Keywords = ropa naftowa] OR [Subject and Keywords = statystyki] OR [Title = Statystyka Naftowa = Statistique Pétrole. R. 5, 1930, nr 1, z. 2]