Unfortunately, I am unable to browse the internet or provide specific recommendations for resources outside of my training data. However, I can offer some general suggestions on how to find books or resources that provide detailed solutions to previous years' Agriculture Optional papers.

1. Previous Years' Question Papers:
Start by collecting previous years' question papers for the Agriculture Optional subject. These papers will give you a clear idea of the type of questions asked in the exam and the level of difficulty.

2. Check Official UPSC Website:
Visit the official website of the Union Public Service Commission (UPSC) and browse through their archives. They often provide previous years' question papers and their respective answer keys. These official solutions can be a reliable resource for understanding the correct approach and scoring well in the Agriculture Optional papers.

3. Books and Study Materials:
Look for books and study materials specifically designed for the Agriculture Optional subject. Some popular books include:

- "Agricultural Engineering" by R.K. Jain
- "Agricultural Economics and Farm Management" by G. Subba Reddy
- "Principles of Agronomy" by Yellamanda Reddy and G.H. Sankara Reddy
- "Principles of Plant Breeding" by B.D. Singh

These books often include solved previous years' papers, detailed explanations, and practice questions. They can be helpful in understanding the concepts and improving your problem-solving skills.

4. Online Platforms:
Explore online platforms such as EduRev, which provide a wide range of study materials, including solved papers and detailed solutions. You can search for Agriculture Optional papers on EduRev and find resources that suit your requirements.

Remember to cross-check the accuracy of solutions provided in any resource and refer to official sources whenever possible. Practice solving previous years' papers under timed conditions to improve your speed and accuracy. Regular practice and revision will help you gain confidence and excel in the Agriculture Optional papers.

In conclusion, by collecting previous years' question papers, referring to official UPSC sources, using recommended books and study materials, and exploring online platforms like EduRev, you can find detailed solutions to previous years' Agriculture Optional papers.