1. Expansion of the mid-palatal suture studied by means of metallic implants;Krebs;Trans. Eur. Orthod. Soc.,1958
2. Mid-palatal suture expansion studied by the implant method over a seven year period;Krebs;Trans. Eur. Orthod. Soc.,1964
3. Changes in nasal airway resistance associated with rapid maxillary expansion;Hershey;Am. J. Orthod.,1976
4. Changes in nasal airflow incident to rapid maxillary expansion;Wertz;Angle Orthod.,1968
5. Skeletal and dental changes accompanying rapid midpalatal suture opening;Wertz;Am. J. Orthod.,1970