If you are looking for reviews of a book entitled, The Democratization of American Christianity, by Nathan O. Hatch, published in 1989, JSTOR is a good starting place. From the basic search screen, simply type the following string:
rt: "democratization of american christianity"
where rt stands for "reviewed title," followed by a colon and the title of the book enclosed in quotation marks.
The full text of the review is available by clicking on the citation.