Perhaps you should try some spelling variations:
tinh tinh » trinh tinh, tinh ninh, tinh binh
hieu van » hieu va, thien van, lieu va
dua tren » dung tren
cau tren » cu tren, dau tren, ca tren
so sach » so sanh, bo sach, co sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
nang xa » nang x, lang xa, nang ma
dao xuc » dao duc, dao tuc, dao xu
va tinh » may tinh
xuc va » duc va, tuc va, luc va

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ty nang xa hoi. hieu van dao xuc va tinh tinh ((dua tren) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ty nang xa hoi. hieu van dao xuc va tinh tinh ((dua tren) OR (cau tren)).
• Adding a wildcard symbol may retrieve word variants: so sach ty nang xa hoi. hieu van dao xuc va tinh tinh ((dua tren) or (cau tren))*.