Firstdown,
Did you even read the link you provided? Serious question. It states clearly that these sources are asking for Romney to release his returns. Your link even said it and cites the same exact people I just provided.
The National Review *did* call on Romney to release his tax returns.
Release the Returns - The Editors - National Review Online
Pete Sessions
He was asked the question, should Romney release his tax returns. His response?
"His personal finances, the way he does things, his record, are fair game," Texas Republican Pete Sessions told CNN.
Umm..sounds like Sessions is calling on him release his damn tax returns.