Perhaps you should try some spelling variations:
thien van » thi van
sach ky » sach y, sach ty, sach kem
va hanh » van hanh, va thanh, va danh
ca tren » cau tren, cu tren, co tren
la tren » loai tren, dua tren, dat tren
sac ky » cac ky, sai ky
nam tu » nam thu, nam thuc
x hoi » xa hoi, o hoi, x ho

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 ky) or (sac ky)) nang x hoi. thien van nam tu va hanh vi ((ca tren) OR (la tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sac ky)) nang x hoi. thien van nam tu va hanh vi ((ca tren) OR (la tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) or (sac ky)) nang x hoi. thien van nam tu va hanh vi ((ca tren) OR (la tren))".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sac ky)) nang x hoi. thien van nam tu va hanh vi ((ca tren) OR (la tren))*.