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
dinh dau » dinh dat, dinh du, danh dau
cham tuc » nham thuc, pham thuc, tham thuc
dau cua » dai cua, day cua, cau cua
va dinh » van dinh, va kinh, va tinh
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
tuc va » thuc va, truc va, tuc xa

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) or (nang ma)) hoi. ((thien van) or (thi nang)) cham tuc va dinh dau cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky ((nang xa) OR (nang ma)) hoi. ((thien van) OR (thi nang)) cham tuc va dinh dau cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach ky ((nang xa) or (nang ma)) hoi. ((thien van) or (thi nang)) cham tuc va dinh dau cua tre*.