Yes. You provided one. And there might even be two, but that would be too many to properly tally.
Yes, I provided the one in most recent memory, from literally hours ago.
- When the WaPo article came out saying that Sally Yates had warned the White House that Flynn had lied to the public and Pence about his conversations with the Russian ambassador, the White House fired Flynn the same day, then made a big deal, which continues up to today, about "unmasking" and "leakers." I hope even you can understand that a false story is incompatible with leaking classified information. It's either one or the other, not both.
- In March, several stories indicated that Flynn would ask for immunity. This was then confirmed by many sitting members of Congress in subsequent stories, and in a letter from Flynn's attorney.
- Starting from October of last year up through March of this year, there were scads of press reports mentioning an FBI investigation into Russian interference in the election, including possible collusion with the Trump campaign. Comey verified the existence of this investigation on March 20 in his testimony before the House Intel Committee. While styled as a "bombshell" by many commentators, it really wasn't all that much of a bombshell to anyone who had been reading the newspapers for the past several months.
- When Trump fired Comey, numerous reports came out within hours saying that White House officials had said the real reason Trump fired Comey was that he was "fuming over the Russia investigation." Trump proceeded to confirm this first to the Russians, then in a TV interview with Lester Holt.
- In the aforementioned conversation that Trump had with the Russian ambassador and foreign minister, a report stated that Trump had disclosed classified information. The White House later verified this, claiming that he nevertheless didn't reveal any information to suggest the identity of the source.
- A separate leak from that same conversation said that Trump told the Russians that Comey was a "nutjob" and that he fired Comey to relieve the pressure from the Russia investigation. Also verified by the White House.
- the story about Kushner asking for a back channel with the Russians received a "no comment" from the White House, but numerous people associated with the administration, and GOP in Congress, have either attempted to justify it by saying there is nothing wrong with a back channel, or else condemning it (as with McCain.) The "no comment" alone is close enough verification even without Trump's Secretary of Homeland Security defending Kushner's behavior in a TV interview.
- when in January CNN, citing anonymous sources, reported that Trump and Obama had been briefed by Clapper about the Steele dossier, the fact that this briefing took place was verified by Obama, Biden, Clapper and ultimately, Trump himself.
You now have 9 examples. That's what I came up with off the top of my head in 5 minutes here, without googling around to look for more.
Edit: adding another example which occurred to me later. I think I'll keep updating this for whenever this "anonymous sources are bunk" argument gets made. Feel free to just link to this list.