The impact of extraction protocol on the chemical profile of cannabis extracts from a single cultivar
GNU自由文档许可证（簡稱GFDL）是一个公共版权个授權，好拨自由文件引用个。2000年个辰光，伊由自由软件基金会創造出来。
链接进来
- Guide to the new drafts of documentation licenses
- GFDL official text
- Free Software and Free Manuals, essay by Richard Stallman
- Why Wikivoyage isn't GFDL: Problems with using the GFDL for short printed texts
