Perhaps you should try some spelling variations:
hoc thuc » hoc huu
van hanh » van thanh, ban hanh, van anh
te sach » toc sach
sach tu » sach thu, cach tu, sach ty
tu tong » tu tuong, tu trong, tu dong
tong xa » thong xa, trong xa, song xa
hieu va » lieu va, hieu qua
co thuc » do thuc, co thua, mo thuc
lai cua » hai cua, lai chau, thai cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach tu tong xa hoi. hieu va ((co thuc) or (hoc thuc)) van hanh ((dai cua) or (lai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach tu tong xa hoi. hieu va ((co thuc) OR (hoc thuc)) van hanh ((dai cua) OR (lai cua)) tre.
• Adding a wildcard symbol may retrieve word variants: te sach tu tong xa hoi. hieu va ((co thuc) or (hoc thuc)) van hanh ((dai cua) or (lai cua)) tre*.