Operator`s manual

The designations employed and the presentation of material

throughout this book do not imply the expression of any opinion

whatsoever on the part of the Food and Agriculture Organization

(FAO) concerning the legal or development status of any country,

territory, city, or area or of its authorities, or concerning the

delimitations of its frontiers or boundaries.

The authors are responsible for the choice and the presentation

of the facts contained in this book and for the opinions expressed

therein, which are not necessarily those of FAO and do not commit

the Organization.