Reddit mentions of The Hongzhou School of Chan Buddhism in Eighth- through Tenth-Century China

Unlocking the Zen Koan: A New Translation of the Zen Classic Wumenguam has been helpful. Also, reading Red Pine's translations and commentary on the The Platform Sutra: The Zen Teaching of Hui-neng, Heart Sutra and Diamond Sutra. Although many people speak of the influence of the Lankavatara on Zen, I find it very difficult to read, even Red Pine's fairly approachable translation. But, the idea of "no views" and "no perceptions" was helpful, and "to speak of [this] to to speak of not [this]". Those themes come up often in koans. And studying Lao Tsu helps. Despite what the "not zen" crowd says, a background in Mahayana Buddhism and Taoism, and some historical background really does help a lot. Currently reading Ordinary Mind as the Way: The Hongzhou School and the Growth of Chan Buddhism and The Hongzhou School of Chan Buddhism in Eighth- through Tenth-Century China to get some background on Mazu's lineage. Like many westerners, I used to think koans were just about derailing rational thought. While that is useful, now I also see some patterns, a certain amount of "sense", and more experiences of "of course". Easier koans like, it is your mind that moves help with the more difficult ones. Another helpful one is What are you doing? What are you saying?.

No, not an academic, especially in religious studies or Chinese history, unless maybe an amateur.

I think Jeffrey L. Broughton following in McCrae's footsteps, was remarking on Baso, in 1675 CE Japan, unsuccessfully attempting to yet again for the umpteenth time, trying to re-fabricate Chinese history. After the shine had worn off of DT Suzuki in the late 70's until a decade or so ago, Soto practitioners like McCrae had come to the fore with an anti iconoclastic agenda, but they rightfully pointed out that the source materials needed to be re-examined in the light of political agendas. But with the academics of the last decade, even McCrae's agendas are being exposed. For example:

The Hongzhou School of Chan Buddhism Jinhua Jia http://www.amazon.com/Hongzhou-Buddhism-Eighth-through-Tenth-Century/dp/0791468240

The Power of Patriarchs: Qisong and Lineage in Chinese Buddhism, Elizabeth A. Morrison (esp pages 30 to 50)

I am not talking about a "pure" Zen. Neither are Jinhua Jia or Morrison. In fact Jia and Morrison are not even really looking at a Zen that was not "a branch of Buddhism", since they both seem to accept McCrae's thesis that "encounter dialogue" was a fabrication of a literati class in the late Tang (800 CE).

In these two books, you will find evidence that zen was not a religious lineage until later Buddhists decided to make it so. In these two books you will see how later Buddhists transformed the characters of Zen like Bodhidharma and Mazu into proper Buddhist priests who espoused the doctrine.

But for a more thorough view of the Taoist and Confucian China out of which "encounter dialogue" arose in 600 BCE, may I suggest Ray Grigg, The Tao of Zen, less academic, but still a well cited book.