@techreport{kam977,
 author = {Z. Dvo\v{r}\'ak, D. Kr{\'a}l', and R. Thomas},
 title = {Three-coloring triangle-free graphs on surfaces I.\\        Extending a coloring to a disk with one triangle},
 institution = {KAM-DIMATIA Series},
 year = {2010},
 number = {977},
 type = {prepublication}
}