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CONTRIBUTING.md

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+# Contributing to doi2dataset
+
+Thank you for your interest in contributing to **doi2dataset**! We welcome contributions from the community and appreciate your help in making this project better.
+
+## Quick Start
+
+1. **Fork** the repository on GitLab
+2. **Clone** your fork locally:
+   ```bash
+   git clone https://git.uni-due.de/your-username/doi2dataset.git
+   cd doi2dataset
+   ```
+3. **Install** development dependencies:
+   ```bash
+   pip install -r requirements-dev.txt
+   ```
+4. **Make** your changes
+5. **Test** your changes (see [Testing](#testing) below)
+6. **Submit** a pull request
+
+## How to Contribute
+
+### Reporting Issues
+
+- Use the GitLab issue tracker to report bugs or request features
+- Provide clear descriptions and steps to reproduce issues
+- Include relevant system information and error messages
+
+### Code Contributions
+
+- Create a new branch for your feature or bug fix
+- Write clear, descriptive commit messages
+- Follow the existing code style and conventions
+- Add tests for new functionality
+- Update documentation as needed
+- Ensure all tests pass before submitting
+
+### Documentation
+
+- Documentation is built using Sphinx and deployed automatically
+- Source files are in `docs/source/`
+- See the [full documentation](https://doi2dataset-66f763.gitpages.uni) for more details
+
+## Development Setup
+
+### Prerequisites
+
+- Python 3.7+
+- pip
+
+### Installation
+
+```bash
+# Clone the repository
+git clone https://git.uni-due.de/your-username/doi2dataset.git
+cd doi2dataset
+
+# Install development dependencies
+pip install -r requirements-dev.txt
+
+# Install documentation dependencies (optional)
+pip install -r requirements-doc.txt
+```
+
+## Testing
+
+We use pytest for testing with comprehensive coverage of core functionalities.
+
+### Running Tests
+
+```bash
+# Run all tests
+pytest
+
+# Run with coverage
+pytest --cov=.
+
+# Generate HTML coverage report
+pytest --cov=. --cov-report=html
+```
+
+### Test Structure
+
+Tests are organized into several files covering:
+- Core functionality (DOI validation, name processing)
+- API integration (mock responses)
+- Citation building
+- Metadata processing
+- License processing
+- Publication utilities
+
+## Code Style
+
+- Follow existing code conventions
+- Write clear, descriptive variable and function names
+- Add docstrings for public functions and classes
+- Use type hints where appropriate
+- Keep functions focused and modular
+
+## Documentation
+
+### Building Documentation Locally
+
+```bash
+# Build current branch documentation
+cd docs
+make html
+
+# Build multiversion documentation
+cd docs
+make multiversion
+```
+
+The documentation supports multiple versions and is automatically deployed via GitLab CI/CD.
+
+## Submitting Changes
+
+1. **Create a branch** from `main` for your changes
+2. **Make your changes** with appropriate tests
+3. **Ensure all tests pass**
+4. **Update documentation** if needed
+5. **Submit a merge request** with:
+   - Clear description of changes
+   - Reference to related issues
+   - List of testing performed
+
+## Need Help?
+
+For detailed information about contributing, building documentation, testing, and development setup, please refer to our comprehensive [Contributing Guide](https://doi2dataset-66f763.gitpages.uni/contributing.html) in the documentation.
+
+## Code of Conduct
+
+Please be respectful and constructive in all interactions. We aim to maintain a welcoming environment for all contributors.
+
+## Questions?
+
+If you have questions about contributing, feel free to:
+- Open an issue for discussion
+- Check the existing documentation
+- Contact the maintainers
+
+Thank you for contributing to doi2dataset! 🚀