"Proto" - Laura Spinney. Proto-Indoeuropean. https://www.powells.com/book/proto-how-one-ancient-language-... (https://www.powells.com/book/proto-how-one-ancient-language-went-global-9781639732586?condition=New) before that "The Horse the Wheel & Language". David Anthony. Proto-Indoeuropeans. https://www.powells.com/book/horse-the-wheel-language-how-br... (https://www.powells.com/book/horse-the-wheel-language-how-bronze-age-riders-from-the-eurasian-steppes-shaped-the-modern-world-9780691148182?condition=New)
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