Tài liệu tham khảo WikiPedia: Xe lăn http://mentalfloss.com/article/20768/who-invented-... http://blogs.static.mentalfloss.com/blogs/archives... http://www.wheelchair-information.com/history-of-w... http://www.bbc.co.uk/ahistoryoftheworld/objects/qc... https://www.thoughtco.com/history-of-the-wheelchai... https://www.wired.com/design/2012/05/wheelchair/
