Perhaps you should try some spelling variations:
thien van » thi van
tham thuc » pham thuc, tam thuc, thai thuc
nham thuc » nhan thuc, nam thuc, nham thu
toc sach » hoc sach, doc sach, thuoc sach
kinh dai » sinh dai, kinh dao, kinh hai
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
va kinh » va tinh, qua kinh
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 ((tham thuc) or (nham thuc)) va kinh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky nang xa hoi. thien van ((tham thuc) OR (nham thuc)) va kinh dai cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach ky nang xa hoi. thien van ((tham thuc) or (nham thuc)) va kinh dai cua tre*.