Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
cau phuc » cau truc, chau phu, huu phuc
cu tren » dua tren
ca tren » cau tren, la tren, co tren
sach ky » sac ky, sach y, sach ty
tu tren » tu truyen, tu tieng, tu trong
phuc va » phuc vu, thuc va, chuc va
hieu ve » hieu va, hieu van
ve cau » ke cau, va cau, ve cac
dau va » dau ve, lau va
va dau » va dao
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: hoc sach ky nang x hoi. hieu ve cau phuc va dau va ((ca tren) or (((cu tren) OR (tu tren))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ky nang x hoi. hieu ve cau phuc va dau va ((ca tren) OR (((cu tren) OR (tu tren)))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach ky nang x hoi. hieu ve cau phuc va dau va ((ca tren) or (((cu tren) OR (tu tren))))".
• Adding a wildcard symbol may retrieve word variants: hoc sach ky nang x hoi. hieu ve cau phuc va dau va ((ca tren) or (((cu tren) OR (tu tren))))*.