CPA works in a public accounting firm and as part of his work represents clients before the Department of the Treasury, generally to challenge notifications of tax deficiencies. In a particular case, the CPA located, in the following sources of law, the answer to successfully defend a client:

1. Internal Revenue Code 2.Jurisprudence of the Supreme Court of Puerto Rico 3. Instructions for the Corporate Income Tax Return. 4. Tax Text 5. Regulations of the Department of the Treasury 6. Blog about tax aspects of corporations

Indicate which or which of these sources the CPA cannot cite when defending its client before the Department of the Treasury. Justify your answer