The Religious Society of Friends began in the 1600's during the English Christian reformation. At that time the English Bible was the spiritual text readily available, and interpretation thereof hotly debated. For many generations thereafter the spiritual understanding was shaped and formed by the particular Friendly way of scripture interpretation which held in tension the scriptural text and individual Divine revelation. With the Religious Society of Friends opening to the world that occurred after World War I and World War II eastern non-programmed Friends received into membership people of all religious back grounds. With them came a variety of religious texts and ways of knowing God. The tension continues to provide a good balance and check on personal revelation and literal interpretation. Below are some links to religious texts that modern eastern non-programmed friends have found useful in better understanding our Christian roots.
Torah - https://www.sefaria.org/texts
Quran - https://al-quran.info/#home
Buddhist Texts - https://fore.yale.edu/World-Religions/Buddhism/Misc/Sacred-Texts