Perhaps you should try some spelling variations:
nhanh hai » nhanh thai, thanh hai, nhanh ha
cau tren » cu tren, dau tren, ca tren
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
hanh hai » thanh hai, hang hai, hanh tai
hieu van » hieu va, thien van, lieu va
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
nang xa » lang xa, nang ma, mang xa
van cac » van hac, van cau, van bac

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 ky ((nang xa) or (nang x)) hoi. hieu van cac nuoc va ((hanh hai) or (nhanh hai)) cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky ((nang xa) OR (nang x)) hoi. hieu van cac nuoc va ((hanh hai) OR (nhanh hai)) cau tren.
• Adding a wildcard symbol may retrieve word variants: vu sach ky ((nang xa) or (nang x)) hoi. hieu van cac nuoc va ((hanh hai) or (nhanh hai)) cau tren*.