Citations needed 

Thank you for your addition to Premenstrual syndrome.  I have corrected a few small errors and moved part of it to the ==History== section.  

Your information needs to be supported by WP:Citations to WP:Reliable sources, such as the books or articles that the direct quotations were copied from.  Please try to add those.  If it's too hard to figure out, then do your best, or leave a note at Talk:Premenstrual syndrome with the names of the books, the authors, and other appropriate information, and someone else will try to fix it for you.  

Thanks,