Generally, the number of words in papers with intermediate titles is about 3000 words, and there is no stipulation on what to mainly discuss. However, the required content is consistent with your declared major and cannot deviate too far. Co-writing is ok, but only if you are the first author. It must be published, and it must be published in regular journals. Now a lot of them are lies. You can consider the modern commercial trade industry. Their papers are included in full in HowNet. You can visit official website.