WORLD OF LAKES (CONTINUED).PEARL RM.1978; EARTH SCI.; U.S.A.; DA. 1978; VOL. 31; NO 3; PP. 75-76; 1 ILL.Article

EARTH'S ACTIVE CRUST.PEARL RM.1977; EARTH SCI.; U.S.A.; DA. 1977; VOL. 30; NO 5; PP. 203-205Article

METEORITES IN ALASKA AND HAWAII.PEARL RM.1977; EARTH SCI.; U.S.A.; DA. 1977; VOL. 30; NO 2; PP. 92Article

NEW ENGLAND METEORITES.PEARL RM.1976; EARTH SCI.; U.S.A.; DA. 1976; VOL. 29; NO 6; PP. 289-290Article

SKIN AND BONES.PEARL RM.1976; EARTH SCI.; U.S.A.; DA. 1976; VOL. 29; NO 2; PP. 93-95; 5 ILL.Article

STONE RAINBOWS.PEARL RM.1976; EARTH SCI.; U.S.A.; DA. 1976; VOL. 29; NO 5; PP. 246-252; 5 ILL.Article

FOOTPRINTS IN THE MUD.PEARL RM.1975; EARTH SCI.; FRA; 1975, VOL. 28, NUM. 0001, P. 36 A 37Serial Issue

WATERFALLS: AN EXPLANATION.PEARL RM.1975; EARTH SCI.; FRA; 1975, VOL. 28, NUM. 0001, P. 23 A 35Serial Issue

HANDBOOK FOR PROSPECTORS.PEARL RM.sdNEW YORK MCGRAW-HILL; 5. ED,1973, P. 1 A 480Book

EARTH'S ACTIVE CRUST. (CONTINUED)PEARL RM.1978; EARTH SCI.; USA; DA. 1978; VOL. 31; NO 4; PP. 176-178Article

GEM COLORS.PEARL RM.1978; EARTH SCI.; U.S.A.; DA. 1978; VOL. 31; NO 1; PP. 19-20Article

WORLD OF LAKES (CONTINUED).PEARL RM.1978; EARTH SCI.; U.S.A.; DA. 1978; VOL. 31; NO 1; PP. 34-35Article

WATERFALLS: AN EXPLANATION.PEARL RM.1975; EARTH SCI.; USA; 1975, VOL. 28, NUM. 0003, P. 147 A 154Serial Issue

EARTH'S ACTIVE CRUST. WHAT MAKES THEM MOVE.PEARL RM.1979; EARTH SCI.; USA; DA. 1979; VOL. 32; NO 2; PP. 88-90Article

EARTH'S ACTIVE CRUST (CONTINUED)PEARL RM.1978; EARTH SCI.; USA; DA. 1978; VOL. 31; NO 5; PP. 225-227Article

EARTH'S ACTIVE CRUST, THE PLATES IN THE PASTPEARL RM.1978; EARTH SCI.; USA; DA. 1978-1979; VOL. 32; NO 1; PP. 37-38Article

STONE RAINBOWS.PEARL RM.1977; EARTH SCI.; U.S.A.; DA. 1977; VOL. 30; NO 1; PP. 24-28; 3 ILL.Article

WORLD OF LAKES.PEARL RM.1977; EARTH SCI.; U.S.A.; DA. 1977; VOL. 30; NO 6; PP. 254-256Article

CRETACEOUS CREATURES.PEARL RM.1976; EARTH SCI.; U.S.A.; DA. 1976; VOL. 29; NO 1; PP. 9-13; 7 ILL.Article

WATERFALLS: AN EXPLANATION. GROUP H, ARTIFICIAL WATERFALLS.PEARL RM.1975; EARTH SCI.; U.S.A.; 1975, VOL. 28, NUM. 0005, P. 242 A 251Serial Issue

ROCKS IN THEIR HEADS OR MAN VS. MINERALPEARL RM.1973; EARTH SCI.; U.S.A. ; 1973, VOL. 26, NUM. 0004, P. 206 A 208Serial Issue

GEOLOGY IS, WHAT GEOLOGISTS DO. IDENTIFYING PLAGIOCLASEPEARL RM.1979; EARTH SCI.; USA; DA. 1979; VOL. 32; NO 4; PP. 160-161Article

EARTH'S ACTIVE CRUST (CONTINUED).PEARL RM.1978; EARTH SCI.; U.S.A.; DA. 1978; VOL. 31; NO 3; PP. 125-128Article

WORLD OF LAKES.PEARL RM.1977; EARTH SCI.; U.S.A.; DA. 1977; VOL. 30; NO 3-4; PP. 133-149 (6P.); 4 ILL.Article

END OF THE DINOSAURS.PEARL RM.1976; EARTH SCI.; U.S.A.; DA. 1976; VOL. 29; NO 3; PP. 127-132; 8 ILL.Article