Here is an article titled Building A Solid Jazz Chord Foundation by Curt Sheller, published in the November 2004 issue of Just Jazz Guitar magazine.

Here is an article titled Getting Beyond Guitar Shapes by Curt Sheller, published in the May 2004 issue of Just Jazz Guitar magazine that utilizes the principles covered in the book The Six Secrets of Guitar Fingering.

Note: All principles mentioned in the guitar articles are approporiate for ukulele players a well.