Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
va phan » van phan, va phat, va phap
van han » van hanh, van phan, van nhan
tai cua » thai cua, tai cuc, tri cua
cua tre » cua te, cuu tre, cua triet
va nam » van nam, ha nam, va nay
va han » va hanh, va hang, va chan

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky nang xa hoi. lieu va nam thu ((((va han) OR (va phan))) or (van han)) tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang xa hoi. lieu va nam thu ((((va han) OR (va phan))) OR (van han)) tai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang xa hoi. lieu va nam thu ((((va han) OR (va phan))) or (van han)) tai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang xa hoi. lieu va nam thu ((((va han) OR (va phan))) or (van han)) tai cua tre*.