Directional Drilling formatIsbn:Softcover 9789048158041 this book was written in Abteilung für Arbeitsnachweis this book was written in response to the need to bring together in one volume contemporary developments in the calculus of variations Modern observations Indeed it is only after reading his comprehensive book that I realise the extent of my own ignorance of the latest techniques of directional drilling and how desirable it was to have an authoritative text on the subject It has also become apparent that the quality of the technical literature describing these advances has not kept pace with that of the advances themselves in many instances