Articles in scholarly journals must have citations and footnotes, and generally go through a peer-review process.
About Book Reviews: Book reviews are included in most scholarly journals. Another way to search for scholarly book review is by searching a book title in Library Search, When you search for book reviews or scholarly articles, pay attention to the citations and notice what scholarly journal your article or review is published in.
H-Net - H-Asia is a great source for book reviews of scholarly titles. H-Net is the one of the exceptions to the rule about avoiding academic articles and book reviews found online. This is a reliable website administered from University of Michigan's History Department and contribute to by an "international interdisciplinary organization of scholars and teachers".