As a result, the government not only lost a great amount of potential tax money from the producers and distributors of alcohol, but also initiated the appearance and rapid development of numerous criminal organizations that received most of their incomes from bootlegging (illegal alcohol trade). As it is clearly seen, this entire situation was quite natural and easy to predict. When something becomes hard to come by, while not ceasing to be a desired commodity, it becomes expensive. When there is a lack of supply for an expensive commodity, however dangerous its production and distribution is, there appear people who want to make money on it, and they won’t disappear until the law that brought them into existence disappears.
Notice that since I took a direct quote from John Smith's book, I placed those words in quotation marks. Notice also that I placed the date that the book was published directly after the author's name in parentheses--this is proper APA format. Finally, notice that because I explained WHO wrote the book and WHAT book it comes from, the reader is easily able not only to find the source on his/her own to check my facts, but the reader is also more likely to believe what I have to say now that they know that my information comes from a credible source.