Perhaps you should try some spelling variations:
mlanh hai » thanh hai, minh hai, lang hai
lanh hai » thanh hai, lang chai, lanh dao
manh hai » minh hai, thanh hai, van hai
quoc ban » quoc bao, quoc lan, quoc quan
tu sach » thu sach, su sach, te sach
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu va, hieu van
cuu tre » cua tre, cau tren, cau treo
y nang » ky nang, ly nang, v nang
ve han » ve hanh, ve phan, ve ban
ma hoi » mai hoi, xa hoi, ma hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach y nang ma hoi. hieu ve han quoc ban ((lanh hai) or (((mlanh hai) OR (manh hai)))) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang ma hoi. hieu ve han quoc ban ((lanh hai) OR (((mlanh hai) OR (manh hai)))) cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang ma hoi. hieu ve han quoc ban ((lanh hai) or (((mlanh hai) OR (manh hai)))) cuu tre".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang ma hoi. hieu ve han quoc ban ((lanh hai) or (((mlanh hai) OR (manh hai)))) cuu tre*.