I'm trying to find a children's book by Colin & Jacqui Hawkins?

I don't know the name. I remember reading it when I was a boy around early to mid 1980's. The only thing I can remember is that one of the illustrations had a picture of a cartoon Vlad the Impaler peering around the corner of a castle (I think!) asking "Any Turks"? I've been hunting for this book for years and would love any help. Even if anyone knows how I can contact the authors would be a great help.