Perhaps you should try some spelling variations:
thien van » thi van
toc sach » hoc sach, doc sach, thuoc sach
thi nang » thi cong, ki nang, thi hanh
cham tuc » nham thuc, pham thuc, tham thuc
dinh dau » dinh dat, dinh du, danh dau
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
xa dinh » xac dinh, va dinh, ba dinh
cua tre » cuu tre, cua triet, dua tren
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ky nang xa hoi. ((thien van) or (thi nang)) cham tuc xa dinh dau ((cua tre) OR (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky nang xa hoi. ((thien van) OR (thi nang)) cham tuc xa dinh dau ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky nang xa hoi. ((thien van) or (thi nang)) cham tuc xa dinh dau ((cua tre) OR (cua te))".
• Adding a wildcard symbol may retrieve word variants: toc sach ky nang xa hoi. ((thien van) or (thi nang)) cham tuc xa dinh dau ((cua tre) OR (cua te))*.