Perhaps you should try some spelling variations:
lang dao » lanh dao, lang cao, lang dai
dua tren » dung tren
tu sach » thu sach, su sach, tu cach
te sach » toc sach
ky dang » ky nang, ky danh
dang xa » dang xay, lang xa, dang ha
hieu ke » hieu kem, chieu ke, hieu ky
cau loc » hau loc, cau hoc, cau luc
va lang » va nang, hoa lang
ke cau » ket cau
loc va » hoc va, luc va
cua te » cua tu

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) or (te sach)) ky dang xa hoi. hieu ke cau loc va lang dao ((dua tren) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) ky dang xa hoi. hieu ke cau loc va lang dao ((dua tren) OR (cua te)).
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (te sach)) ky dang xa hoi. hieu ke cau loc va lang dao ((dua tren) or (cua te))*.