Perhaps you should try some spelling variations:
dinh vai » dinh van, dinh vi, dinh va
va dinh » van dinh, va kinh, va tinh
sach ky » sac ky, sach ty, sach kem
hieu va » lieu va, hieu qua
cu tren » tu tren, dua tren
lang xa » lang ha, dang xay, lang van
vai cu » vai cua, van cu
cam o » cham o, cam lo, tam o
ca o » co o, va o

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 ky) OR (sach y)) lang xa hoi. hieu va ((cam o) or (ca o)) va dinh vai cu tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach ky) OR (sach y)) lang xa hoi. hieu va ((cam o) OR (ca o)) va dinh vai cu tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu ((sach ky) OR (sach y)) lang xa hoi. hieu va ((cam o) or (ca o)) va dinh vai cu tren".
• Adding a wildcard symbol may retrieve word variants: thu ((sach ky) OR (sach y)) lang xa hoi. hieu va ((cam o) or (ca o)) va dinh vai cu tren*.