what is the best reference books when you are doing research????

Today, just to share the best research book for undergraduate or postgraduate as their reference if they do a business research. According to my supervisor Assoc. Prof Dr. Norzaidi and his wife Dr.Intan Salwani they suggested to use this 2 famous book:

1)"Research method for business" wrote by Uma Sakaran & Roger Bougie.
2) "Business Research: a practical guide for undergraduate and postgraduate students" wrote by Jill Hussey & Roger Hussey.

Honestly,  I'm prefer to use the second book that. it is because the word and the sentence on this book is easy to understand especially for me who are poor in English and not a business student. FYI,I do bachelor degree in Civil  Engineering but when i do my Master (MSc.), i has been change it to business. it quite tough for me to learn starting from zero knowledge but i'm feel lucky after i read that book, wrote by hussey&hussey (1997).
For PhD candidate i'm most prefer to all of you to use Uma Sakaran book. it is because it's more advance and have a few example to you to become more understanding. My suggestion to all of you if you read Uma Sakaran book, please refer to expert one also to make it easy for you to understand and not run away from the track.
Actually, there are a lot of books out there that we can use or share the knowledge on it. here i just wanna share my opinion about "what is the best reference books when you are doing research" based on my experience only......You are also invited to share your knowledge and experience with me...!!! c ya