Finding previous years' papers with detailed explanations and solutions can be a valuable resource for exam preparation, especially for competitive exams like the UPSC. These papers provide insight into the type of questions asked, the exam pattern, and allow for practice and self-assessment. Here are some ways to find such resources:

1. Official UPSC Websites:
- The official UPSC website (https://www.upsc.gov.in) provides access to previous years' question papers along with their answers.
- Candidates can visit the "Previous Question Papers" section on the website to find papers from previous years.

2. Educational Websites:
- EduRev (https://www.edurev.in) is a reliable and comprehensive educational platform that offers a wide range of previous years' papers with detailed explanations and solutions.
- Users can search for specific exam papers, and EduRev provides access to a vast collection of solved papers, including those for UPSC exams.

3. Coaching Institute Websites:
- Many coaching institutes that specialize in UPSC exam preparation provide previous years' papers with detailed explanations on their websites.
- These coaching institutes often have dedicated sections or resources where candidates can access and download the papers.

4. Online Forums and Communities:
- There are various online forums and communities where aspirants share resources, including previous years' papers with solutions.
- Websites like Quora, Reddit, and UPSC discussion forums can be helpful in finding links and recommendations for such resources.

5. Mobile Apps:
- Several mobile apps cater to the needs of UPSC aspirants and provide access to a wide range of previous years' papers with explanations and solutions.
- Apps like "UPSC IAS All in One - Study for UPSC CSE" and "ClearIAS - UPSC CSE IAS IPS IRS Exam Prep" offer comprehensive study materials, including solved papers.

It is important to note that while there are multiple platforms offering such resources, it is advisable to rely on trusted sources like the official UPSC website and reputed educational platforms like EduRev. These resources provide accurate and reliable information, ensuring a better learning experience.