For what may be called scattered information you can go to the American Library Association Index to general literature, The Information Quarterly (Bowker), The Book Review Digest (Wilson), The United States Catalog (with its annual Cumulative Book Index), and the (annual) English Catalogue of Books.
In using a book, employ the Table of Contents and the Index to save time. For example, you will thus be referred to page 157 for what you want. If instead you begin to hunt page by page, you will find that after you have patiently run your eyes back and forth over the first 156 pages, your brain will be less responsive than you would wish when you finally arrive at page 157. Moreover, there is all that time lost!
Often individual libraries have compiled lists of their own books on various subjects. If you can find such lists, use them.
In other words, the search for material and the taking of notes is a matter of strategy: it requires that the seeker use his wits, plan his campaign, find what is available, and in the briefest time compatible with thoroughness assimilate whatever of it is of value. Caution and indefatigable zeal and resourcefulness—these are almost sure to win the day.
[1] George Gissing: The Private Papers of Henry Ryecroft. By permission of the publishers, E. P. Dutton & Co., New York City.
[2] Words were made to conceal our thoughts.
[3] A. G. Gardiner: Prophets, Priests, and Kings. By permission of the publishers, E. P. Dutton & Co., New York City.
[4] George Gissing: The Private Papers of Henry Ryecroft, "Summer," XXI. By permission of the publishers, E. P. Dutton & Co., New York City.
[5] Stacy Aumonier, in The Century Magazine, December, 1917. By courtesy of the publisher, The Century Company, New York City.
[6] Ralph Waldo Emerson: "Fate," The Conduct of Life. Houghton Mifflin Company, publishers, Boston.