Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
truc van » truc va, thuc van, truc ban
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
van cau » van dau, van hau, van chat
vai cua » hai cua, lai cua, bai cua

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 cau truc van hanh ((vai cua) or (dai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang xa hoi. hieu van cau truc van hanh ((vai cua) OR (dai cua)) tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang xa hoi. hieu van cau truc van hanh ((vai cua) or (dai cua)) tre*.