Reshebniki are usually specific to a particular textbook or publisher:
A "Reshebnik" (GDZ) for 8th-grade geography contour maps is a collection of completed maps and answers to tasks provided in educational workbooks. These resources are designed to help students check their work or understand how to correctly display geographic data like borders, climate zones, and natural resources. Popular Publishers for 8th Grade Maps
Often includes complex thematic tasks regarding population and economy.