

Hunting for hidden gold
1920
ISBN 9780515159073
The Secret of the Old Mill
1927
ISBN 9780486851464
While the Clock Ticked
1932
ISBN 9780448433134
The Tower Treasure
1927
ISBN 9780807207666
The Missing Chums
1928
ISBN 9780001605329
The Secret Warning
1938
ISBN 9780001605510
The Mark on the Door
1934
ISBN 9781101064832
Night of the Werewolf
2009
ISBN 9781101065242
The Sign of the Crooked Arrow
1949
ISBN 9780006910398
The Hooded Hawk Mystery
1954
ISBN 9780006918035
Footprints Under the Window
1933
ISBN 9781557092700
The Great Airport Mystery
1930
ISBN 9780006917410
What Happened at Midnight
1931
ISBN 9780448089102
The Melted Coins
1944
ISBN 9780006909101
Mystery of the Desert Giant
1960
ISBN 9780006909323
The House on the Cliff
1927
ISBN 9780448433042
The Mystery of the Spiral Bridge
1965
ISBN 9781101065143
The Witchmaster's Key
1975
ISBN 9780001605565
The Mystery of Cabin Island
1929
ISBN 9781557092663
Mystery of the Whale Tattoo
1967
ISBN 9781101065167
The Secret of the Lost Tunnel
1950
ISBN 9780006928379
The Infinity Clue
1981
ISBN 9780671691547
The flickering torch mystery
1943
ISBN 9780448189222
The Clue in the Embers
1955
ISBN 9780448089355