Dear Sister ,
Have been so busy with other subjects on his website like as-salat and others. i look up every one of the refereces for my self , so as you can guess it is quite time consuming, so i have not come to the subject of saum. but you can always call him or write to him, if not i will try to do it for you although it can take quite a time. but inshaAllah will try to remember that point.