Mukhya Upanishads

Mukhya Upanishads, also known as Principal Upanishads, are the most ancient and widely studied Upanishads of Hinduism. Composed between 800 BCE to the start of common era, these texts are connected to the Vedic tradition.
Content.
According to most Hinduism traditions 10 Upanishads are considered as Mukhya Upanishads, but some scholars now are including , and into the list. The founders of the major schools of Vedanta, viz, Adi Shankara and Madhvacharya wrote ("commentaries") on these ten Principal Upanishads. Even though Ramanuja did not write individual commentaries on Mukhya Upanishads, he quoted many hundreds of quotations from Upanishads in his Sri Bhasya. In Ramanuja lineage one of his follower by the name Rangaramanuja wrote commentaries on almost all the ten Mukhya Upanishads in around 1600.
The adjective "" means "principal", "chief", or "primary". The Mukhya Upanishads are accepted as śruti by all Hindus, or the most important scriptures of Hinduism. 
The 10 Mukhya Upanishads are:
Translations and works.
Here is the list of works on Upanishads: