If you can't find a person in a census index, try reversing their first and last names. It is possible the census taker (or other record keeper) made a simple goof. Foreign language names can easily get recorded in this way.
This could easily explain why Panagiotis Verikios was enumerated in 1930 as Verikios Panagiotis.
Think about it--it's possible with English language as well.