Perhaps you should try some spelling variations:
tinh ban » tinh bang, trinh ban, tinh bac
dau tren » dau tien, dat tren, dau tieng
sach ky » sach y, sach ty, sach kem
van dau » van dao, phan dau
va tinh » may tinh
ban dau » bat dau, ban dan, hang dau
sac ky » cac ky, sai ky
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 ((sach ky) or (sac ky)) nang x hoi. hieu ((van nam) or (van dau)) tu va tinh ban dau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ky) OR (sac ky)) nang x hoi. hieu ((van nam) OR (van dau)) tu va tinh ban dau tren.
• Adding a wildcard symbol may retrieve word variants: te ((sach ky) or (sac ky)) nang x hoi. hieu ((van nam) or (van dau)) tu va tinh ban dau tren*.