How To Play Double-Nine Deduction

About Double-Nine Deduction, from BoardGameGeek:

Double-Nine Deduction is a print n' play cooperative deduction game for 2-4 players. The goal of the game is to play 26 dominoes onto a shared player board so that each of the dominoes played connects to an existing domino chain on the board. Players cannot see the faces of their dominoes and must give clues to the other player(s) to help them deduce what's on their domino faces. Clues are simple on the surface (identify eligible pairs of domino ends that have a specific sum or difference), but can lead to some truly satisfying deductive moments. Double-Nine Deduction plays well at all player counts, and is a rare case of a cooperative deduction game that shines at two-player. -description from the designer