Unfortunately, unsigned artworks are rarely attributed to a specific artist. There are just too many paintings in the world, and so many are by amateur artists. Unless you have a possible name to work with, your painting may well remain a mystery. However, if you are convinced that your item is of some value you could either commission a specialist researcher or seek the advice of an auction house with a dedicated art specialist on the team. A certain amount of this work can be undertaken via the internet, but be aware that a true and accurate valuation cannot be provided without your valuer seeing the item in person. The reason for this is that it is impossible to be positive that a painting is original, not a print or copy and not a forgery, purely by seeing photographs.