Obtain monthly data for various asset classes?

I am attempting to obtain monthly data for several asset classes dating back to 1970, which can be used as a proxy for various ETFs such as:

EEM
TLT
SPY
GLD
PDBC (dbc)
VNQ

I’ve found something here: https://www.investing.com/commodities/gold-historical-data

However, does anyone know of any other sites where long-term, monthly asset class data may be found?

Give this site a try.

https://eodhistoricaldata.com/

I have never used data from that site but feel their pricing is reasonable. I can’t speak to their accuracy.

Steve