ODDITIES OF THE MINERAL WORLD:
THE SAND SPIKES FROM MOUNT SIGNAL
by William B. Sanborn

RAREZAS DEL MUNDO MINERAL:
LAS PUNTAS DE ARENA DEL CENTINELA [en español],
por William B. Sanborn

SAND CONCRETIONS FROM CALIFORNIA,
by S. C. Edwards

CONCRECIONES DE ARENA DE CALIFORNIA [en español],
por S. C. Edwards

TREASURES OF THE BADLANDS,
by Frank Dunn

TESOROS DE LAS TIERRAS ESTÉRILES [en español],
por Frank Dunn

CONCRETIONS NEAR MT. SIGNAL, LOWER CALIFORNIA,
by Kenneth B. Garner

SANDSTONE CONCRETIONS OF THE COLORADO DELTA,
by Guy E. Hazen

MOUNT SIGNAL CONCRETIONS,
by Eva May Hyde

A TRIP TO A CONCRETION LOCALITY,
by Edmund F. Kiessling

UN VIAJE A UNA ZONA DE CONCRECIONES [en español],
por Edmund F. Kiessling

IMPERIAL VALLEY CONCRETIONS:
THERE ARE SOME WEIRD SHAPES IN THE CALIFORNIA DESERT,
by James R. Mitchell

MEXICAN BORDER SAND SPIKES
IN CALIFORNIA'S COLORADO DESERT,
by Jay Ellis Ransom

NEW FORMS OF CONCRETIONS,
by H. W. Nichols

THE FORMATION OF SANDSTONE CONCRETIONS,
by George P. Merril

WE DUG SANDSPIKES AT THE BORDER . . .,
by Harold O. Weight

SCIENTISTS HAVE A NEW EXPLANATION FOR
MYSTERIOUS SAND SPIKES,
by Katherine Kornei

CONCRETIONS,
by Bob Katz

CONCRETIONS, BOMBS, AND GROUND WATER,
by Peter S. Mozley

CARBONATE CONCRETIONS: A BIBLIOGRAPHY,
compiled by R.V.Dietrich

JEAN ARP's HUMAN CONCRETION

EDWARD WESTON's SANDSTONE CONCRETION, SALTON SEA