Helios, more fully the Helios New Encyclopedic Dictionary ( or: ÃÂõÃÂÃÂõÃÂÿý ÃÂóúàúûÿÃÂñùôùúÃÂý ÃÂõþùúÃÂý ÃÂûùÿÃÂ), is a general knowledge Greek encyclopaedia. Its publication commenced in 1945 while its second edition was completed in 1960, comprising a total of 18 volumes.