Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hoc sach » hoc sinh, hoc cac, hoc anh
tuan lai » tuan tai, xuan lai, tuong lai
hieu va » lieu va, hieu qua
va phan » van phan, va phat, va phap
duc van » duc va, duc manh, duc phan
chau te » chau tho
nang o » nang co, nang ho, nang ro
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((thu sach) or (hoc sach)) ky nang o hoi. hieu va phan ((duc van) OR (duc tan)) tuan lai chau te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (hoc sach)) ky nang o hoi. hieu va phan ((duc van) OR (duc tan)) tuan lai chau te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) or (hoc sach)) ky nang o hoi. hieu va phan ((duc van) OR (duc tan)) tuan lai chau te".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (hoc sach)) ky nang o hoi. hieu va phan ((duc van) OR (duc tan)) tuan lai chau te*.