Various Happy Hollister Editions
Doubleday Book Club Edition
Distinguishing Characteristics - no price on dust jacket flap or the words Book Club on dust jacket flap.
Doubleday Regular Edition
Distinguishing Characteristics - price on dust jacket flap.
Garden City Edition
Distinguishing Characteristics - The words Garden City on the lower spine of each book.
Grosset & Dunlap Edition
Distinguishing Characteristics - Grosset & Dunlap on lower spine of each book. Different size than other editions and different cover art, which is not created by Helen S. Hamilton.
Distinguishing Characteristics - Light yellow book cover, no dust jackets. Color picture of the Hollister children (not the same black print as the other editions). Same picture throughout series in this edition, but the colors of that picture are different on each book in this edition.
Distinguishing Characteristics - Titled "Los Felices Hollister". I do not yet have this edition and can not tell you the main distinguishing characteristics, but I can tell you that it is in the Spanish language and should be fairly easy to seperate from other editions.
Distinguishing Characteristics - Patricia in Maine(from a guestbook entry) says "I recently saw a copy of the Happy Hollisters that was written in French. So, I guess they published in French as well.".
Distinguishing Characteristics - Titles such as "og Fyr-Lyktens Hemme-Lighet" (At Sea Gull Beach), "og Fortets Hemme-Lighet" (The Secret Fort), "og Spokelses-Hesten" (Ghost Horse Mystery), "og Ballong-Mysteriet" (Castle Rock Mystery), "og Ekko-Mysteriet" (Swiss Echo Mystery) and "og Mysteriet I Alaska" (Mystery of Totem Faces). The dust jacket graphics appear to be much "brighter" in colors than the American versions and the pictures, while the same or similar - are cut at different angles. For example, on the "Secret Fort" issue, the dirt shovel isn't entirely shown (the graphic is centered more to the right than the left), therefore, it appears to look slightly different.