Softtech: 212 books

The world is changing at an exceedingly rapid pace. Life seems to have become much more demanding and stressful over the last several decades. We've officially entered the Age of Information that is being ruled by computers, smartphones, and a constant stream of information that we have a need to...

In this book the author has tried to combine the trade information which he has gained in his avocation, the study of precious stones, with the scientific knowledge bearing thereon, which his vocation, the teaching of chemistry, has compelled him to master. In planning and in writing the book,...