APA

Bulg. Found. for Energy Efficiency EnEffect, . (1994). ECOENERGY. Sofia: Bulg. Found. for Energy Efficiency EnEffect.

Chicago

Bulg. Found. for Energy Efficiency EnEffect, . 1994. ECOENERGY. Sofia: Bulg. Found. for Energy Efficiency EnEffect.

Harvard

Bulg. Found. for Energy Efficiency EnEffect, . (1994). ECOENERGY. Sofia: Bulg. Found. for Energy Efficiency EnEffect.

MLA

Bulg. Found. for Energy Efficiency EnEffect, . ECOENERGY. Sofia: Bulg. Found. for Energy Efficiency EnEffect. 1994.