Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hanh doi » thanh doi, hanh noi, hang doi
van hanh » van thanh, ban hanh, van anh
nuoc van » nuoc va, nuoc san, luoc van
doi cua » dai cua, hoi cua
hang xa » hoang xa, hang va, hang ca
ly hang » ly quang
cua tu » cua tuc, cua su, cua cu
hien » bien, tien, dien

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) or (toc sach)) ly hang xa hoi. hieu ((vien dai) OR (hien dai)) nuoc van hanh doi cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ly hang xa hoi. hieu ((vien dai) OR (hien dai)) nuoc van hanh doi cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) ly hang xa hoi. hieu ((vien dai) OR (hien dai)) nuoc van hanh doi cua tu".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ly hang xa hoi. hieu ((vien dai) OR (hien dai)) nuoc van hanh doi cua tu*.