Is Partialism a real heresy?

This YouTube video identifies Partialism as a heresy. It states that Partialism is the heresy wherein The Father, Son, and Holy Spirit are each described as 1/3 of God. To me, it's a vaguely familiar false understanding of the Trinity; but I can't find any solid information about it. **Are there any historical documents, early Church writings, or documents from a major denomination (Catholicism, Eastern Orthodox, Lutheran, etc.) that assert this idea *by this or any other name* as a heresy or false understanding of the Trinity?** If the condemnation of this idea can't be pinned directly to a historical document or Church Father, when can we reasonably assert that it was condemned, if ever? --- Per [Peter Turner](https://christianity.stackexchange.com/users/4/peter-turner) , the wikipedia page on Partialism is an [occasion of sin](http://en.wikipedia.org/wiki/Occasion_of_sin) . I have not attempted to verify this, but the relevant Wikipedia page is the one on [divine simplicity](https://en.wikipedia.org/wiki/Divine_simplicity) .