Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
doc sach » hoc sach, toc sach, nuoc sach
hieu va » lieu va, hieu qua
vuc van » duc van, luc van, thuc van
cac vuc » cac nuoc, cac vung, cac cuoc
te sach » toc sach
hang ma » hang va, hang ca, tang ma
ty hang » ly hang, ty xang, thi hang
cua cay » cua cac
ma hoi » mai hoi, xa hoi, ma hoa
cua cu » cua chu, cua cau, cua su

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) or (doc sach)) ty hang ma hoi. hieu va cac vuc van hanh vi ((cua cu) or (cua cay))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (doc sach)) ty hang ma hoi. hieu va cac vuc van hanh vi ((cua cu) OR (cua cay)).
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (doc sach)) ty hang ma hoi. hieu va cac vuc van hanh vi ((cua cu) or (cua cay))*.