However, a more substantial reason for the noted diversity is one of historical nature. In a 1979 work on the history of the Gbe peoples (called "Adjatado" back then), the Catholic missionary Roberto Pazzi pointed out that 'three dialects emerged from the half-breeding between immigrant groups and the indigenes from Tádó: they are Gɛ̀n, Sáhwè and Xweɖá.' . The latter two dialects are part of Capo's Phla–Pherá branch, and Capo adds that Tsáphɛ and Phelá have Cábɛ (Yoruboid) and E̟do respectively as substrata. This contact and intermingling of non-Gbe peoples with Gbe peoples and the influence of this processes on language inevitably diffuses the picture presented by comparative linguistic research. Further research into the historical origins of the Phla and Pherá peoples has yet to take place .