Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, te sach, tu cach
su sach » so sach, vu sach
nang xa » nang x, lang xa, nang ma
cua van » cua ban, cua vat, cua dan
bai cua » ban cua, bai ca, hai 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) OR (su sach)) ky nang xa hoi. hieu van nam cua van hanh ((bai cua) or (dai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky nang xa hoi. hieu van nam cua van hanh ((bai cua) OR (dai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (su sach)) ky nang xa hoi. hieu van nam cua van hanh ((bai cua) or (dai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (su sach)) ky nang xa hoi. hieu van nam cua van hanh ((bai cua) or (dai cua)) tre*.