Reading up on $BQP = BPP^{BQNC}$
This was conjectured by R. Jozsa in Section 8 of arXiv:quant-ph/0508124. If you are already familiar with quantum computing and quantum complexity theory, you can start by reading that section.

An important reading is arXiv:quant-ph/0006004, where Cleve and Watrous show that Shor's algorithm is in that class.