Wordnet polsko-angielski 
                         (from 544 million to about 500 million years ago
marine invertebrates) 
Cambrian, Cambrian period 
Nowoczesny słownik polsko-angielski 
                        the Cambrian
 (from 544 million to about 500 million years ago
marine invertebrates) 
Cambrian, Cambrian period 
the Cambrian