- Cărți electroniceSouthwest Treasure Hunter's Gem and Mineral Guide (6th Edition)Kathy J. Rygle
- Cărți electroniceSoutheast Treasure Hunter's Gem & Mineral Guide (6th Edition)Kathy J. Rygle
- Cărți electroniceNortheast Treasure Hunter's Gem & Mineral Guide (5th Edition)Kathy J. Rygle
- Cărți electroniceNorthwest Treasure Hunter's Gem and Mineral Guide (6th Edition)Kathy J. Rygle
- Cărți electroniceNorthwest Treasure Hunter's Gem and Mineral Guide (5th Edition)Kathy J. Rygle
- Cărți electroniceNortheast Treasure Hunter's Gem and Mineral Guide (6th Edition)Kathy J. Rygle