Perhaps you should try some spelling variations:
dau tren » dau tien, dat tren, dau tieng
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
hieu ve » hieu va, hieu van
cao duc » dao duc, cao suc, giao duc
cu tren » tu tren, dua tren
ve cao » va cao, ve bao, ve cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ty nang x ho. hieu ve cao duc va ((hanh kem) or (hanh vi)) ((cu tren) or (dau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty nang x ho. hieu ve cao duc va ((hanh kem) OR (hanh vi)) ((cu tren) OR (dau tren)).
• Adding a wildcard symbol may retrieve word variants: su sach ty nang x ho. hieu ve cao duc va ((hanh kem) or (hanh vi)) ((cu tren) or (dau tren))*.