  The origin of carbon-enhanced metal-poor stars enriched with both s and r
elements is highly debated. Detailed abundances of these types of stars are
crucial to understand the nature of their progenitors. The aim of this
investigation is to study in detail the abundances of SDSS J1349-0229, SDSS
J0912+0216 and SDSS J1036+1212, three dwarf CEMP stars, selected from the Sloan
Digital Sky Survey. Using high resolution VLT/UVES spectra (R ~ 30 000) we
determine abundances for Li, C, N, O, Na, Mg, Al, Ca, Sc, Ti, Cr, Mn, Fe, Co,
Ni and 21 neutron-capture elements. We made use of CO^5BOLD 3D hydrodynamical
model atmospheres in the analysis of the carbon, nitrogen and oxygen
abundances. NLTE corrections for C I and O I lines were computed using the Kiel
code. We classify SDSS J1349-0229 and SDSS J0912+0216 as CEMP-r+s stars. SDSS
J1036+1212 belongs to the class CEMP-no/s, with enhanced Ba, but deficient Sr,
of which it is the third member discovered to date. Radial-velocity variations
have been observed in SDSS J1349-0229, providing evidence that it is a member
of a binary system. The chemical composition of the three stars is generally
compatible with mass transfer from an AGB companion. However, many details
remain difficult to explain. Most notably of those are the abundance of Li at
the level of the Spite plateau in SDSS J1036+1212 and the large over-abundance
of the pure r-process element Eu in all three stars.
