The data is from the FEC complied by the Center for Responsive Politics (opensecrets.org).
5min on the FEC's website and I found this:
https://www.fec.gov/data/candidate/S...tion_full=true
Who is is second largest outside supporter? In fact he was their number #2 most supported candidate via independent expenditures alone (they have many ways to shuffle money to candidates, one of their arguments that they only directly gave him $9,000)