- Libro electrónicoSouthwest Treasure Hunter's Gem and Mineral Guide (6th Edition)Kathy J. Rygle
- Libro electrónicoSoutheast Treasure Hunter's Gem & Mineral Guide (6th Edition)Kathy J. Rygle
- Libro electrónicoNortheast Treasure Hunter's Gem & Mineral Guide (5th Edition)Kathy J. Rygle
- Libro electrónicoNorthwest Treasure Hunter's Gem and Mineral Guide (6th Edition)Kathy J. Rygle
- Libro electrónicoSouthwest Treasure Hunter's Gem and Mineral Guide (5th ed.)Kathy J. Rygle
- Libro electrónicoNorthwest Treasure Hunter's Gem and Mineral Guide (5th Edition)Kathy J. Rygle
- Libro electrónicoNortheast Treasure Hunter's Gem and Mineral Guide (6th Edition)Kathy J. Rygle
- Libro electrónicoSoutheast Treasure Hunter's Gem & Mineral Guide (5th Edition)Kathy J. Rygle