The Accounting Principles Board (APB) was the precursor to the Financial Accounting Standards Board (FASB).
APB opinions, statements and interpretations were published in FASB's Accounting Standards: Original Pronouncements and the AICPA's Opinions of the Accounting Principles Board. Original Pronouncements was published in print and on the FARS CD-ROM. Historical editions may still be available through CCH's Accounting Research Manager and through RIA's Checkpoint.