 The upper boundary (earliest date) assigned to the Germanic parent language is described as "dialectal Indo-European".In the works of both Van Coetsem and Voyles, attempts are made to reconstruct aspects of this stage of the language using a process the former refers to as "inverted reconstruction"; i.e.one using the data made available through the attested daughter languages in light of and at times in preference to the results of the "comparative reconstruction" undertaken to arrive at Proto-Indo-European.