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