Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
toc sach » hoc sach, doc sach, thuoc sach
cham tuc » nham thuc, pham thuc, cham soc
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
thi van » thi lan, thi hanh, thi nang
dan dau » danh dau, doan dau, van dau
dau cua » dai cua, day cua, cau cua
cua tre » cua te, cuu tre, cua triet

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