Optimization of the heat and power cogenerationValdma, MatiSeminar on District Heating and Electricity Cogeneration : 20-21 May, 1999, Tallinn : proceedings1999 / p. 55-58 Role of CHP in the development of Estonian energeticsLiik, OlevSeminar on District Heating and Electricity Cogeneration : 20-21 May, 1999, Tallinn : proceedings1999 / p. 27-37: ill