Perhaps you should try some spelling variations:
hanh vinh » thanh vinh, khanh vinh, hanh tinh
toc sach » hoc sach, doc sach, thuoc sach
tan hanh » tan thanh, tang hanh, toan hanh
dua tren » dung tren
hieu van » hieu va, thien van, lieu va
bac dan » bach dan, cac dan, bac dai
sach ky » sac ky, sach y, sach ty
nang ha » nang hai, nang han, nang hoa
cuu tre » cua tre, cau tren, cau treo
ban dan » ban hang, ban hanh, ban quan
ha hoi » hoa hoi, ha noi, xa hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ky nang ha hoi. hieu van ((bac dan) or (ban dan)) tan hanh vinh ((cuu tre) or (dua tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky nang ha hoi. hieu van ((bac dan) OR (ban dan)) tan hanh vinh ((cuu tre) OR (dua tren)).
• Adding a wildcard symbol may retrieve word variants: toc sach ky nang ha hoi. hieu van ((bac dan) or (ban dan)) tan hanh vinh ((cuu tre) or (dua tren))*.