Books in Children's Book Series (sorted alphabetically)
- Pee-wee Harris Adrift Percy Keese Fitzhugh
- Pee-wee Harris on the Trail Percy Keese Fitzhugh
- Peggy Stewart at School Gabrielle E. Jackson
- Peggy Stewart, Navy Girl, at Home Gabrielle E. Jackson
- Pluck on the Long Trail; Or, Boy Scouts in the Rockies Edwin L. Sabin
- Polly and Eleanor Lillian Elizabeth Roy
- Polly of Pebbly Pit Lillian Elizabeth Roy
- Polly's Business Venture Lillian Elizabeth Roy
- Princess Polly At Play Amy Brooks
- Princess Polly's Gay Winter Amy Brooks
- Princess Polly's Playmates Amy Brooks
- Prudy Keeping House Sophie May
- Puritan Twins Lucy Fitch Perkins
- Queen Hildegarde Laura Elizabeth Howe Richards
- Radio Boys Cronies; Or, Bill Brown's Radio Wayne Whipple and S. F. Aaron
- Radio Boys' First Wireless; Or, Winning the Ferberton Prize Allen Chapman
- Radio Boys in the Thousand Islands; Or, The Yankee-Canadian Wireless Trail Frank Honeywell
- Radio Boys Loyalty; Or, Bill Brown Listens In Wayne Whipple and S. F. Aaron
- Radio Boys on the Mexican Border Gerald Breckenridge
- Radio Boys Trailing a Voice; Or, Solving a Wireless Mystery Allen Chapman
- Ranger Boys and the Border Smugglers Claude A. LaBelle
- Red Cross Girls with the Russian Army Margaret Vandercook
- Rollo at Play; Or, Safe Amusements Jacob Abbott
- Rollo at Work Jacob Abbott
- Rollo in Geneva Jacob Abbott