I just found the leading edge textbook was enough, i find in business though that its helpful to have a whole bunch of resources so i'll basically look at my DE classwork, the textbook and online for stuff I don't understand.
Generally business' studies is trying to relate the stuff you learn to business' you've seen in real life so maybe like what 'wrecking' said just looking at case studies and stuff, or even going to visit a business and asking the owner's some questions
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