ACKNOWLEDGEMENT The inspiration to write this book came from may sources; the most primary of which is God, the Almighty Creator and Originator; the Able and Capable, the One and Only-Allahu. To Him is my unreserved gratitude and appreciation in recognition of His Bounties, His Guidance and His Protection over my entire family members this far. My gratitude also goes to the Rector of the Polytechnic, Dr.Razaq Bello and the entire members of his management team, whose leadership style has afforded the congenial environment under which such a work as this was possible. Deserving a special mention here is the place of, and the role played by my darling wife, my precious gift; Tawakalitu Allah Lahi, for providing the real familial environment needed for the attainment of this goal. She did not only provide the much-needed psycho-emotional and physical stability on the home front, she was the brain behind the word processing on the home system all through. No amount of expression can describe enough her wonderful contributions to the success of this work. Mr. B.O. Saliu, Chief Lecturer in Mathematics and Statistics Department and Director, Academic Planning, the Federal Polytechnic, Offa, who, painstakingly, read through the manuscript, despite his ever-tight schedules. Except for the sound and thorough reading of the manuscript as did by Mr. Saliu, those far-reaching corrections and other suggestions as were made by him would not have been possible. Not only these, his accepting to write the foreword to this book added up to my load of indebtedness to him. Indeed, I owe much of my exposure and experience to Professor Doris O. Bozimo, former HOD, Library and Information Science, ABU Zaria, and now, University Librarian, mentor and academic role model, her leadership in the Department afforded me the privilege of serving in many research- related committees in and outside of my Department then. To me, all these have now turned into an invaluable asset of some sort. To the Professor, my gratitude remains eternal; for she was not only instrumental to my securing the appointment in ABU, Zaria, in the early academic growth and maturity; part of which is this work. To all other individuals, too numerous to mention, who had contributed to the successful completion of this book, one way or the other, and especially my colleagues here in the Department, I thank you very sincerely.