Look at the graph.
2 answers:
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1) There are two main types of historical sources: primary sources and secondary sources
2) there are three types of sources
1) primary sources
2) secondary sources
3) tertiary sources
1) primary sources = Primary sources are documents, images or artifacts that provide firsthand testimony or direct evidence concerning an historical topic under research investigationter
2) secondary sources = Secondary sources often offer review or a critique. Secondary sources can include books, journal articles, speeches, reviews, research reports, and more
3) tertiary sources = A tertiary source is an index or textual consolidation of primary and secondary sources