Perhaps you should try some spelling variations:
dat thanh » dao thanh, dat khanh, dang thanh
vat thanh » gat thanh, tat thanh, viet thanh
bach ky » bac ky
hieu va » lieu va, hieu qua
co thuc » do thuc, co thua, mo thuc
tay cua » ty cua
day cua » dai cua
nang o » nang co, nang ho, nang ro
o hoi » co hoi, o hoc, o hai
va co » vo co

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu bach ky nang o hoi. hieu va co thuc ((vat thanh) OR (dat thanh)) ((tay cua) or (day cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu bach ky nang o hoi. hieu va co thuc ((vat thanh) OR (dat thanh)) ((tay cua) OR (day cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu bach ky nang o hoi. hieu va co thuc ((vat thanh) OR (dat thanh)) ((tay cua) or (day cua)) tre".
• Adding a wildcard symbol may retrieve word variants: vu bach ky nang o hoi. hieu va co thuc ((vat thanh) OR (dat thanh)) ((tay cua) or (day cua)) tre*.