Perhaps you should try some spelling variations:
trinh di » trinh do, trinh dien, trinh dinh
cham luc » cham soc, nhan luc, cham cuu
cau tren » cu tren, dau tren, ca tren
lang xa » lang ha, dang xay, lang van
va cham » va chat, va tham
sach ky » sach y, sach ty, sach kem
tinh di » tinh doi, tinh da, tin di
sac ky » cac ky, sai ky
luc va » duc va, tuc va, loc va

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) or (sac ky)) lang xa hoi. lieu va cham luc va ((tinh di) OR (trinh di)) cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((sach ky) OR (sac ky)) lang xa hoi. lieu va cham luc va ((tinh di) OR (trinh di)) cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((sach ky) or (sac ky)) lang xa hoi. lieu va cham luc va ((tinh di) OR (trinh di)) cau tren".
• Adding a wildcard symbol may retrieve word variants: hoc ((sach ky) or (sac ky)) lang xa hoi. lieu va cham luc va ((tinh di) OR (trinh di)) cau tren*.