Eureka (word)
"Eureka" comes from the Ancient Greek word "heúrēka", meaning "I found (it)", which is the first person singular perfect indicative active of the verb "heuriskō" "I find". It is closely related to heuristic, which refers to experience-based techniques for problem solving, learning, and discovery.
Birka
Both Rimbert and Adam were German clergymen writing in Latin. There are no known Norse sources mentioning the name of the settlement, or even the settlement itself, and the original Norse name of Birka is unknown. "Birca" is the Latinised form given in the sources and "Birka" its contemporary, unhistorical Swedish form. The Latin name is probably derived from an Old Norse word "birk" which probably meant a market place. Related to this was the "Bjärköa law" (bjärköarätt) which regulated the life on market places in Denmark, Norway and Sweden. Both terms in different forms are very common in Scandinavian place names still today leading to speculation that all references to Birca especially by Adam of Bremen were not about the same location.