Perhaps you should try some spelling variations:
thien hach » thien thanh, hien hanh
hieu thien » hieu hien, chieu chien, dieu khien
hach nuoc » sach nuoc, hoc nuoc, cac nuoc
va xanh » va danh, va anh, va banh
tai cua » thai cua, tai cuc, tri cua
va hanh » van hanh, va thanh, va danh
nang xa » nang x, lang xa, nang ma
sac ky » cac ky
cua tu » cua tuc, cua su, cua cu

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

• Performing a fuzzy search may retrieve terms with similar spellings: so ((sac ky) or (sai ky)) nang xa hoi. hieu thien hach nuoc ((va xanh) OR (va hanh)) tai cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so ((sac ky) OR (sai ky)) nang xa hoi. hieu thien hach nuoc ((va xanh) OR (va hanh)) tai cua tu*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so ((sac ky) or (sai ky)) nang xa hoi. hieu thien hach nuoc ((va xanh) OR (va hanh)) tai cua tu*".