Introducing the Positions for Violin is written by Harvey S. Whister. The book covers third and fifth positions on the violin. In the foreword by the author, he intends for this book to serve as an introduction to shifting, but not a comprehensive training guide. He suggests that students of the violin should also explore second, third and sixth positions, but only after a thorough development of playing in first, third and fifth positions.
The book begins with some very simple exercises where you prepare, and then begin in the third position. It begins with C Major and has several exercises in that key. The preparation work allows students to begin in tune. It even includes scales and tone exercises. I think these are both very important to position study and development. In each key signature, there are also etudes in various time signatures. If worked through sequentially, these studies should develop not only good position playing, but also good reading skills in those positions.
The shifting exercises cover moving from all fingers. They are quite like Yost exercies. I prefer to lift higher finger numbers and shift with 1 as the guide finger and later dropping the finger needed after the shift. In the shifting exercises by Whistler, a student will slide the 2 or 3 up then drop a 4. I think making 1 the guide finger is more effective in allowing students to keep their hand frame.
The last part of the book has advanced melodic etudes that use the techniques learned in the book.
These exercises should be progressed through very quickly. If they are taken too slowly, it could take years to get through this book. The exercises are somewhat tedious in that respect.
The half step marking in this book is actually the whole step mark that I commonly use. I use a carat to mark a half step instead of a bracket.
The viola edition covers third and half positions. However, the viola book neglects to cover reading in treble clef for the violas. The text is also available for cello.