A series of modifications followed that attempted to correct these problems, leading to the ultimate "S-4" model, but none of these proved fruitful and most work on the pinch concept ended around 1961.
However, none of these proved fruitful, and most work on the pinch concept ended around 1961. A series of modifications followed which attempted to correct these problems, leading to the ultimate "S-4" model.
A series of modifications followed which attempted to correct these problems, leading to the ultimate "S-4" model. However, none of these proved fruitful, and most work on the pinch concept ended around 1961.
A series of modifications followed which attempted to correct these problems, leading to the ultimate "S-4" model. However, none of these proved fruitful, and most work on the pinch concept ended around 1961.