https://www.siliconchip.com.au/Issue/SC/2019/July/El+Cheapo+Modules%3A+AD584+Precision+Voltage+References
El Cheapo Modules: AD584 Precision Voltage References - July 2019 - Silicon Chip Online
Three variations on a theme, all using the AD584 IC from Analog Devices. Obtain highly accurate 2.5V, 5V, 7.5V or 10V references. by Jim Rowe
voltage references