translation.en: There is tremendous sustaining revenue under this long tail to sustain open projects like ours, but also to sustain this new emergence of on-demand publishers, like QOOP, who produced these two books.
translation.zh: 确实存在巨大的可持续收入， 在这个长尾下，支持像我们这样的开源项目， 而且还要支持这种新出现的按需出版商， 比如像出版这两本书的Coop，