Perhaps you should try some spelling variations:
thang hai » thanh hai, thong hai, thanh hoai
cau tren » cu tren, dau tren, ca tren
hang hai » hoang hai, hang tai, thanh hai
cac duc » cac du, cao duc, cac dac
hieu ve » hieu va, hieu van
sac ky » cac ky, sai ky
ve cac » va cac, vien cac
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sac ky) or (sach y)) nang x hoi. hieu ve cac duc va ((hang hai) or (thang hai)) cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sac ky) OR (sach y)) nang x hoi. hieu ve cac duc va ((hang hai) OR (thang hai)) cau tren.
• Adding a wildcard symbol may retrieve word variants: te ((sac ky) or (sach y)) nang x hoi. hieu ve cac duc va ((hang hai) or (thang hai)) cau tren*.