Bharatiya Jyotihshastra (History of Indian Astronomy), translated by R. V. Vaidya v1.c5.83

v1.c5.83

It seems as if the Saṃhitās of Garga and Parāśara belong to a later age. After the knowledge of astronomy had considerably developed it must have been grouped into three divisions or branches including Gaṇita. But this stage must have been preceded by certain works in which all the branches were discussed together. It appears that works of this type did exist and they too were known by the name Saṃhitā. Varāhamihira says in his Bṛhat Saṃhitā :—