From the front of the book:
This material was originally published as three separate adventures; G1 (Steading of the Giant Chief), G2 (The Glacial Rift of the Frost Giant Jarl), and G3 (Hall of the Fire Giant King). Contained herein are referee notes, background information, maps, and exploration keys for three complete adventures using the Advanced Dungeons & Dragons[tm] rules. This module can be used alone or as the first in a series of adventures that includes Dungeon Modules D1-2 (Descent into the Depths of the Earth), D3 (Vault of the Drow), and Q1 (Queen of the Demonweb Pits).
Origins '79 Tournament Module