dejiny objavov a vynálezov 2 [vynechat] history of discoveries and inventions 2 [vynechat] computers 1 [vynechat] discoveries and inventions 1 [vynechat] inventors 1 [vynechat] objavitelia a vynálezcovia 1 [vynechat] objavy a vynálezy 1 [vynechat] počítače 1 [vynechat] radio engineering 1 [vynechat] rádiotechnika 1 [vynechat] television 1 [vynechat] televízia 1 [vynechat]