If you want to study SDA history, read the periodical articles on the SDA archives site [too many]. You can also do topical studies on EGW sites. I'm posting articles on the Jesuits from old Review articles. Once you find a topic which interests you, for example "investigative judgment," plug it into a search of pioneer writings to find the writings of various individuals.
You can also download .pdf files of periodical articles and use the search function to identify terms such as "Jesuits" "Investigative Judgment," "make" or "declare" righteous. Maintain a narrow focus. Specific time period, specific topic. For early SDA history, EGW's lifetime is the limit
I once took an independent study course with Fred Veltman. First I wanted to study the Biblical doctrine of perfection. Too big a topic, he said, for a single quarter course. We finally narrowed it down to perfection in the book of Hebrews, which was manageable for a single course. Perfection could have worked for a doctoral thesis, not a single academic quarter. When he did his EGW study, he limited his work to a limited number of chapters. He didn't do the entire book. When I studied Waggoner, I limited the study to his use of the terms "imputation," "make righteous," and "declare righteous." Find the passages which elaborate on the topic rather than just mention it. Avoid special pleading, that is comments which only sustain your prejudices. Waggoner used both terms "make" and "declare" righteous, although his emphasis was on "make righteous" from Romans 5 "many shall be made righteous." Check out Cleansanctuary. blogspot.com for other examples.