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Fig. 4


Sum of CNO elements [(C+N+O)/H] vs. [Fe/H] from various sources down to the lowest [Fe/H] known. The codes for representing stars are the same as in Fig. 1. Upper bounds on [(C+N+O)/H] are indicated by arrows. The brown points at [Fe/H] = −7.1 represent the star SMSS 0313-6708, which has the limits as indicated in the text.

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