Definition: Open information source
R & D - Oslo Manual
Open information sources provide access to knowledge without the need to pay for the knowledge itself, although there may be marginal fees for access (membership in trade associations, attendance at conferences, subscriptions to journals).
Organization for Economic Cooperation and Development (OECD) and Statistical Office of the European Communities (Eurostat), "The measurement of scientific and technological activities: guidelines for collecting and interpreting innovation data: Oslo manual)", Third Edition, Paris, 2005, par. 265