The present work has been written jointly by the two co-authors. Nathif Jama Adam has contributed the section on "Sources of Happiness". Ghalib Ahmad Masri has written the other sectios of the book.
The authors gratefully acknowledge the efforts that contributed to the production of this booklet in its present form, especially the valuable comments of Dr. Mohamed Lotfi Zlitni and other helpful comments on the content of this work.
The authors gratefully acknowledge the efforts that contributed to the production of this booklet in its present form, especially the valuable comments of Dr. Mohamed Lotfi Zlitni and other helpful comments on the content of this work.
