Perhaps you should try some spelling variations:
thanh hai » thanh phan, thanh hoa, thanh san
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
thuc gia » thuc giai, thue gia, thuc dia
vu sach » vu bach, su sach, vu khach
ty nang » ty xang, ty hang, ly nang
hai cua » thai cua, dai cua, hoi cua
cua tu » cua tuc, cua su, cua cu
o hoa » do hoa, so hoa, o ha
o hoc » co hoc, mo hoc, so hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ((ty nang) or (ky nang)) ((o hoa) or (o hoc)). hieu van nam thuc gia thanh hai cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ((ty nang) OR (ky nang)) ((o hoa) OR (o hoc)). hieu van nam thuc gia thanh hai cua tu.
• Adding a wildcard symbol may retrieve word variants: vu sach ((ty nang) or (ky nang)) ((o hoa) or (o hoc)). hieu van nam thuc gia thanh hai cua tu*.