Готови презентации :

http://www.slideboom.com/presentatio...B5%D0%BC%D0%B8 ..

http://www.slideboom.com/presentatio...B5%D0%BC%D0%B8


http://www.slideboom.com/presentatio...B5%D0%BC%D0%B8


Полезни връзки :
http://ekologiq.zazz.info/?cat=1489

http://ecomedia.bg/doctor-eco/environment/article/3675