div class=ts-pagebutton class=gotoPage data-page=1Page 1button div class=ts-imageimg data-url=-data-sources-and-time-periods-all-collections-are-divided-into-3-time-periodshtmlpage=1 data-page=1 class=ts-thumb lazyload alt=Page 1: imageslibrarywisceduimageslibrarywisceduEcoNatResEFacsDNRBullData Sources and Time Periods All collections are divided into 3 time periods: 1900-31 1959-74 and 1975-81 loading=lazy src=data:imagegifbase64iVBORw0KGgoAAAANSUhEUgAAAAIAAAACCAQAAADYv8WvAAAAD0lEQVR42mP8X8AwAgiABKBAv+vAXklAAAAAElFTkSuQmCC data-src=https:reader033vdocumentsusreader033viewer20220422115eb42f7c4126221f114cbccehtml5thumbnails1jpg width=140 height=200 divdivdiv class=ts-pagebutton class=gotoPage data-page=2Page 2button div class=ts-imageimg data-url=-data-sources-and-time-periods-all-collections-are-divided-into-3-time-periodshtmlpage=2 data-page=2 class=ts-thumb lazyload alt=Page 2: imageslibrarywisceduimageslibrarywisceduEcoNatResEFacsDNRBullData Sources and Time Periods All collections are divided into 3 time periods: 1900-31 1959-74 and 1975-81 loading=lazy src=data:imagegifbase64iVBORw0KGgoAAAANSUhEUgAAAAIAAAACCAQAAADYv8WvAAAAD0lEQVR42mP8X8AwAgiABKBAv+vAXklAAAAAElFTkSuQmCC data-src=https:reader033vdocumentsusreader033viewer20220422115eb42f7c4126221f114cbccehtml5thumbnails2jpg width=140 height=200 divdivdiv class=ts-pagebutton class=gotoPage data-page=3Page 3button div class=ts-imageimg data-url=-data-sources-and-time-periods-all-collections-are-divided-into-3-time-periodshtmlpage=3 data-page=3 class=ts-thumb lazyload alt=Page 3: imageslibrarywisceduimageslibrarywisceduEcoNatResEFacsDNRBullData Sources and Time Periods All collections are divided into 3 time periods: 1900-31 1959-74 and 1975-81 loading=lazy src=data:imagegifbase64iVBORw0KGgoAAAANSUhEUgAAAAIAAAACCAQAAADYv8WvAAAAD0lEQVR42mP8X8AwAgiABKBAv+vAXklAAAAAElFTkSuQmCC data-src=https:reader033vdocumentsusreader033viewer20220422115eb42f7c4126221f114cbccehtml5thumbnails3jpg width=140 height=200 divdivdiv class=ts-pagebutton class=gotoPage data-page=4Page 4button div class=ts-imageimg data-url=-data-sources-and-time-periods-all-collections-are-divided-into-3-time-periodshtmlpage=4 data-page=4 class=ts-thumb lazyload alt=Page 4: imageslibrarywisceduimageslibrarywisceduEcoNatResEFacsDNRBullData Sources and Time Periods All collections are divided into 3 time periods: 1900-31 1959-74 and 1975-81 loading=lazy src=data:imagegifbase64iVBORw0KGgoAAAANSUhEUgAAAAIAAAACCAQAAADYv8WvAAAAD0lEQVR42mP8X8AwAgiABKBAv+vAXklAAAAAElFTkSuQmCC data-src=https:reader033vdocumentsusreader033viewer20220422115eb42f7c4126221f114cbccehtml5thumbnails4jpg width=140 height=200 divdivdiv class=ts-pagebutton class=gotoPage data-page=5Page 5button div class=ts-imageimg data-url=-data-sources-and-time-periods-all-collections-are-divided-into-3-time-periodshtmlpage=5 data-page=5 class=ts-thumb lazyload alt=Page 5: imageslibrarywisceduimageslibrarywisceduEcoNatResEFacsDNRBullData Sources and Time Periods All collections are divided into 3 time periods: 1900-31 1959-74 and 1975-81 loading=lazy src=data:imagegifbase64iVBORw0KGgoAAAANSUhEUgAAAAIAAAACCAQAAADYv8WvAAAAD0lEQVR42mP8X8AwAgiABKBAv+vAXklAAAAAElFTkSuQmCC data-src=https:reader033vdocumentsusreader033viewer20220422115eb42f7c4126221f114cbccehtml5thumbnails5jpg width=140 height=200 divdivdiv class=ts-pagebutton class=gotoPage data-page=6Page 6button div class=ts-imageimg data-url=-data-sources-and-time-periods-all-collections-are-divided-into-3-time-periodshtmlpage=6 data-page=6 class=ts-thumb lazyload alt=Page 6: imageslibrarywisceduimageslibrarywisceduEcoNatResEFacsDNRBullData Sources and Time Periods All collections are divided into 3 time periods: 1900-31 1959-74 and 1975-81 loading=lazy src=data:imagegifbase64iVBORw0KGgoAAAANSUhEUgAAAAIAAAACCAQAAADYv8WvAAAAD0lEQVR42mP8X8AwAgiABKBAv+vAXklAAAAAElFTkSuQmCC data-src=https:reader033vdocumentsusreader033viewer20220422115eb42f7c4126221f114cbccehtml5thumbnails6jpg width=140 height=200 divdiv