Perhaps you should try some spelling variations:
tan hanh » tan thanh, tang hanh, toan hanh
cua viet » hoa viet, cua vat, cua dieu
ca viet » va viet, co viet, hoa viet
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
hanh di » hanh vi, hanh de, hang di
tu san » thu san, tu ban, vu san
ca duc » cao duc, cua duc, ca dua
tu can » tu ban, tu cac, thu canh
qua ca » qua cac, qua cua, qua cai

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu san) or (tu can)) ky lang xa hoi. hieu qua ca duc tan hanh di ((cua viet) OR (ca viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu san) OR (tu can)) ky lang xa hoi. hieu qua ca duc tan hanh di ((cua viet) OR (ca viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu san) or (tu can)) ky lang xa hoi. hieu qua ca duc tan hanh di ((cua viet) OR (ca viet))".
• Adding a wildcard symbol may retrieve word variants: ((tu san) or (tu can)) ky lang xa hoi. hieu qua ca duc tan hanh di ((cua viet) OR (ca viet))*.