Perhaps you should try some spelling variations:
dau tren » dau tien, dat tren, dau tieng
te sach » toc sach
sach ty » sach y, sach tu, sach thu
va hanh » van hanh, va thanh, va danh
cu tren » tu tren, dua tren
ty nang » ky nang, ty xang, ty hang
va dam » van dam, va dau, va dap
va dao » ca dao
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: te sach ty nang x hoi. hieu ((va dam) OR (va dao)) tu va hanh vi ((dau tren) or (cu tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty nang x hoi. hieu ((va dam) OR (va dao)) tu va hanh vi ((dau tren) OR (cu tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty nang x hoi. hieu ((va dam) OR (va dao)) tu va hanh vi ((dau tren) or (cu tren))".
• Adding a wildcard symbol may retrieve word variants: te sach ty nang x hoi. hieu ((va dam) OR (va dao)) tu va hanh vi ((dau tren) or (cu tren))*.