Perhaps you should try some spelling variations:
chiet tach » chieu sach
chieu sang » chieu sach, chieu xanh, hieu lang
hanh trang » thanh trung, canh tranh, hanh trinh
thong dan » thong van, thong den, trong dan
tuong dan » huong dan, tung dan, xuong dan
trang va » tran van, hang va
va thong » va thuong, va phuong, he thong
chan cau » phan cau, can cau, chinh cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((chiet tach) or (chieu sang)) - hanh trang va thong ((thong dan) OR (tuong dan)) chan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chiet tach) OR (chieu sang)) - hanh trang va thong ((thong dan) OR (tuong dan)) chan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((chiet tach) or (chieu sang)) - hanh trang va thong ((thong dan) OR (tuong dan)) chan cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((chiet tach) or (chieu sang)) - hanh trang va thong ((thong dan) OR (tuong dan)) chan cau*.