You can see the Dabao Sutra, Maha Prajna Sutra, Buddhist Tibetan Sutra, Shurangama Sutra, Jue Yuan Sutra, Tanjing, Agama Sutra (Introduction), Forty-two Chapters Sutra, Beijing Sutra and so on.
You'd better look at the Diamond Sutra mentioned by the Buddha first. I know Zen is the most real.
None of those cryptics became Buddhists, and it is impossible to understand the truth of various Buddhism behind closed doors. As the Buddha said, Buddhism is inseparable from the world.
ht tp://yunpan.cn/QG6I6D2BWaMtC