Lithium abundance in unevolved EMP stars. Filled circles refer to carbon-normal stars. CEMP stars of the low- and high-carbon bands are shown as blue stars and grey rectangles, respectively. Upper limits of the programme stars are shown in red. Open red symbols represent the stars for which we find low [n-capture/Fe] upper limit abundances. The blue dashed line represents the Spite Plateau as determined by Sbordone et al. (2010). Details about literature data (black and grey symbols) can be found in Bonifacio et al. (2018). The star SDSSJ002314.00+030758.07 with [Fe/H] < −6.10 dex from Aguado et al. (2019) has been added.