Very confused about these two books

[satone]

<p>So in my first year, there are two classes I am taking which are both pretty introductory and necessary for my intended major. The first is ECON 101, and then MATH 231. </p>

<p>When I tried to purchase my book for ECON 101, I found that my book is called "PRINCIPLES OF ECONOMICS(PKG) CUSTOM BK+CPS CODE CARD New: $92.55
ISBN: 9780077980207"</p>

<p>I tried putting in the ISBN into amazon, half, and other online book stores, and nothing shows, and there are A LOT of books called "Principles of Economics." Because I am trying to save money by buying the book somewhere else, does anyone know anything about the author of this book, and what "PKG, CUSTOM BK+CPS CODE CARD" mean?</p>

<p>For MATH 231, I have two books, one is optional, "SINGLE VARIABLE CALCULUS EARLY TRANSCENDENTAL New: $164.65<br>
ISBN: 9780495011699" This book actually exists.</p>

<p>But my required book DOES NOT EXIST ANYWHERE!!! It's called "CALCULUS(PKG) EARLY TRANSCENDENTALS ALT ED+ENHANCED WEBASSIG New: $148.00<br>
ISBN: 9780495770350"</p>

<p>Can someone tell me which book is used in MATH 231 so I can go and buy it. Thanks!</p>

[saejinbilly]

<p>These books don’t exist elsewhere because they are custom published and intended for the specific classes at UNC. Besides, the MATH 231 course includes webassign code… the evils of which you will learn soon… Personally, I tend to hate these custom publications, but your best bet, other than to buy from friends who’ve already taken the class, is to buy from Student Stores (used, of course).</p>