Coin cell lithium recharging

I was looking at some rechargeable coin cell batteries - does anyone know a good resource for charging lithium coin cells? I thought I would use a LiPo charging circuit, but I looked at a Maxell document and they had the recommended circuit in the attached pic.

I was skeptical because it seems too... simple for a lithium recharging circuit. Does anyone have any experience with these? Thanks!

Link to PDF with circuit:
https://www.electro-tech-online.com/custompdfs/2013/03/ML_12e.pdf

Yeah, way too simple, and lacking information.

-For instance, what is R's value?
-What is the voltage regulator's output voltage?

Other concerns...if the primary voltage dissapears, the load will attempt to power up from the battery. But that series resistor will drop a lot of voltage (depending on the load current, of course). A schotky diode (anode to battery) must be included in parallel.

For those reasons, I would hesitate take this circuit at face value.

EDIT; After reading the link provided, I see that my two first concerns are addressed in the article. However, the diode in parallel with the resistor, does not.

Sorry, I didn't include all the info from the PDF, but they have a table for regulator values vs. resistor values.