Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
danh kien » dinh kien, danh viet, linh kien
thuc va » thuc vat, thuc dan, thuc day
va tham » van tham, va cham, va thanh
sach ky » sac ky, sach y, sach kem
nang xa » nang x, lang xa, nang ma
sach ty » sach y, sach tu, sach thu
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: doc ((sach ky) OR (sach ty)) nang xa hoi. lieu va tham thuc va ((danh kien) or (sinh vien)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((sach ky) OR (sach ty)) nang xa hoi. lieu va tham thuc va ((danh kien) OR (sinh vien)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((sach ky) OR (sach ty)) nang xa hoi. lieu va tham thuc va ((danh kien) or (sinh vien)) cua tre".
• Adding a wildcard symbol may retrieve word variants: doc ((sach ky) OR (sach ty)) nang xa hoi. lieu va tham thuc va ((danh kien) or (sinh vien)) cua tre*.