Perhaps you should try some spelling variations:
giao thanh » gia thanh, gian thanh, giay thanh
thanh hai » thanh phan, thanh hoa, thanh san
tac giao » tac gia, tac giai, tac giam
vu sach » vu bach, su sach, vu khach
nang so » nang som, nang co, nang su
nang ho » nang hoc, nang co, tang ho
sach ky » sac ky, sach y, sach ty
cam tac » cac tac, cam tay, can tac
cua tu » cua tuc, cua cu, cua te
va cam » va cham, va cac, va cao
cua su » qua su

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ky ((nang so) or (nang ho)) hoc. lieu va cam tac giao thanh hai ((cua tu) or (cua su))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky ((nang so) OR (nang ho)) hoc. lieu va cam tac giao thanh hai ((cua tu) OR (cua su)).
• Adding a wildcard symbol may retrieve word variants: vu sach ky ((nang so) or (nang ho)) hoc. lieu va cam tac giao thanh hai ((cua tu) or (cua su))*.