Perhaps you should try some spelling variations:
hoc thuoc » hoc thuc, hoc thuong, hoc nuoc
hieu van » hieu va, thien van, lieu va
hau truc » cau truc, hang truc, hoc truc
va thanh » gia thanh, ban thanh, va tinh
vai cua » dai cua, hai cua, lai cua
va hanh » van hanh, va danh, ban hanh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
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: tu sach ky nang xa hoi. hieu van ((hau truc) or (hoc thuoc)) ((va hanh) or (va thanh)) vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang xa hoi. hieu van ((hau truc) OR (hoc thuoc)) ((va hanh) OR (va thanh)) vai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang xa hoi. hieu van ((hau truc) or (hoc thuoc)) ((va hanh) or (va thanh)) vai cua tre*.