These books provide deep dives into specific areas of competition math, often featuring problems used to train the USA IMO team. 103 Trigonometry Problems

These books (e.g., 102 Combinatorial Problems ) focus on specific sub-disciplines, providing a ladder of difficulty from "introductory" to "IMO level."

: Many of his works, such as Mathematical Olympiad Challenges and Mathematical Olympiad Treasures , are designed to bridge the gap between standard high school curriculum and the sophisticated techniques used in international competitions.

A: Use Adobe Acrobat’s "OCR" (Optical Character Recognition) feature. Many scanned PDFs from 2005 are images. OCR turns math into searchable text (though LaTeX formulas may be garbled).