Perhaps you should try some spelling variations:
viet sach » viet anh, dien sach, viet tech
sach nuoc » sach duoc, cac nuoc, bach tuoc
lieu viet » sieu viet, lieu vien, tieu viet
tinh doi » trinh doc, trinh do, tinh hoc
cau tren » cu tren, dau tren, ca tren
lang xa » lang ha, dang xay, lang van
nang xa » nang x, nang ma, mang xa
xanh di » danh di, vanh dai, xanh tai
xac ky » cac ky, sac ky, bac ky
su xac » pu xac, su cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: su xac ky ((nang xa) OR (lang xa)) hoi. lieu viet sach nuoc va ((tinh doi) or (xanh di)) cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su xac ky ((nang xa) OR (lang xa)) hoi. lieu viet sach nuoc va ((tinh doi) OR (xanh di)) cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su xac ky ((nang xa) OR (lang xa)) hoi. lieu viet sach nuoc va ((tinh doi) or (xanh di)) cau tren".
• Adding a wildcard symbol may retrieve word variants: su xac ky ((nang xa) OR (lang xa)) hoi. lieu viet sach nuoc va ((tinh doi) or (xanh di)) cau tren*.