Perhaps you should try some spelling variations:
ve triet » va trien, su triet
cam thuc » am thuc, nam thuc, cam thu
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
toc sac » toc sach, toc san, hoc sach
dai hoi » dai hoc, dai hai, dai moi
mai hoi » mai khoi, lai hoi, mai doi
ky lang » ky nang, ky dang, ky tang
hieu va » lieu va, hieu qua
sac ky » cac ky, sai ky
va cam » va cham, va cac, va cao
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sac ky lang ((mai hoi) OR (dai hoi)). hieu va cam thuc va hanh vi ((cua te) or (ve triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sac ky lang ((mai hoi) OR (dai hoi)). hieu va cam thuc va hanh vi ((cua te) OR (ve triet))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sac ky lang ((mai hoi) OR (dai hoi)). hieu va cam thuc va hanh vi ((cua te) or (ve triet))*".