[Grammar] "It can be seen that there are, mainly, three sources to obtain information through?

"It can be seen that there are, mainly, three sources to obtain information through?

Hi there,
Can you please correct this sentences I wrote?
"It can be seen that there are, mainly, three sources to obtain information through?
"It can be seen that there are, mainly, three sources through which information can be obtained?

Just let me know if you can notice any wrong with the sentences!

Thanks!

Re: "It can be seen that there are, mainly, three sources to obtain information throu

I much prefer your second offering.

Re: "It can be seen that there are, mainly, three sources to obtain information throu

The two commas before and after 'mainly' could be omitted.
'Through which' could be replaced with 'from which'.

not a teacher