Parks Library has a selection of popular/leisure books on yoga. These materials are not research based. However, they can help you in creating a home practice or in understanding yoga more thoroughly. If we do not own a specific title that you are looking for, you have two options. The first option would be to request the book on interlibrary loan. The second option would be to suggest to me the book as a purchase. I would then add you to the "notification" list, so that you are notified when the book is available for you to check-out from Parks Library. This process usually takes 1-2 months, whereas interlibrary loan usually takes about a week. However, I always appreciate purchase suggestions, even if you do an interlibrary loan for the book.
Current issues of magazines are available in print and can be found in the periodical room
Newspapers are not peer-reviewed scholarly research. However, they can be good sources of information, depending on what type of information you are looking for. As an example, maybe you are doing research on perceptions of and popular writings of yoga. In that case, newspapers could yield information for that type of research.