39 books in series

Hardy-guttene

Hardy-guttene is a 39-book series with 39 primary works first released in 1920 with contributions by Franklin W. Dixon, Jerrold Mundis, and Leslie H. Morrill.

The Tower Treasure

1927 • 39 Readers • 214 pages 3.5

The House on the Cliff

1927 • 19 Readers • 138 pages 3.5

Cover 7

1927 • 3 Readers 3

The Missing Chums

1928 • 8 Readers • 192 pages 3

Hunting for hidden gold

1920 • 9 Readers • 194 pages 3.7

While the Clock Ticked

1932 • 8 Readers • 174 pages 3.6

The Hidden Harbor Mystery

1935 • 5 Readers 3

The Secret Warning

1938 • 5 Readers • 192 pages 3

The clue of the broken blade

1942 • 5 Readers • 192 pages 3

The flickering torch mystery

1943 • 5 Readers • 160 pages 3.3

The Secret Panel

1946 • 7 Readers • 178 pages 3.3

The sign of the crooked arrow

1949 • 4 Readers • 160 pages 3

The Wailing Siren Mystery

1951 • 4 Readers • 177 pages 3

The Yellow Feather Mystery

1953 • 5 Readers • 181 pages 3

The Secret of Pirates' Hill

1956 • 6 Readers • 178 pages 3.3

The Clue in the Embers

1955 • 5 Readers • 214 pages 3

The Ghost at Skeleton Rock

1957 • 5 Readers • 177 pages 3.3

Mystery at Devil's Paw

1959 • 4 Readers • 193 pages 3

The mystery of the Chinese junk

1959 • 4 Readers • 160 pages 3

Mystery of the Desert Giant

1960 • 6 Readers • 160 pages 3.5

The Viking Symbol Mystery

1962 • 4 Readers • 192 pages 3

The mystery of the spiral bridge

1965 • 4 Readers • 160 pages 3

Footprints under the window

1933 • 4 Readers • 157 pages 3

Mystery of the Whale Tattoo

1967 • 4 Readers • 192 pages 3

The great airport mystery

1930 • 6 Readers • 158 pages 3

The Bombay Boomerang

1970 • 3 Readers • 192 pages 3

Masked Monkey

1972 • 4 Readers • 153 pages 3

The Shattered Helmet

1973 • 5 Readers • 180 pages 3.5

The Mysterious Caravan

1975 • 5 Readers • 193 pages 3.3

The Witchmaster's Key

1975 • 3 Readers • 192 pages 3

The Firebird Rocket

1978 • 5 Readers • 192 pages 3

Mystery of Smugglers Cove

1980 • 3 Readers • 181 pages 3

The Vanishing Thieves

1980 • 2 Readers • 179 pages 3

Track of the Zombie

1982 • 1 Reader • 194 pages 3

The Voodoo Plot

1982 • 2 Readers • 189 pages 4

Tic-Tac-Terror

1984 • 1 Reader • 201 pages 3

Trapped at Sea

1982 • 1 Reader • 181 pages 3

Game Plan for Disaster

1982 • 1 Reader 3

The Crimson Flame

1981 • 2 Readers • 190 pages 3.5