Olyeller's silence is deafening. -) If we don't here from him soon, we'll have to conclude that he lied or had Internet problems preventing him from seeing both articles. (I'll give him the benefit of the doubt and assume it was the latter.) Either way, that puts us right back where we were:  Two sources have been provided.  As Sally pointed out, Olyeller promised to add "annual" to the article if two sources were provided.  So, we're all looking forward to Olyeller keeping his promise.