Perhaps you should try some spelling variations:
trach nhiem » trac nghiem
trinh thiet » trinh viet, trinh thi
sach trach » sach tranh, sach truc, sat trach
nhiem van » nghiem van, nhiem va, nghiem ban
thiet de » thiet ke, nhiet de, thiet yeu
thu sach » tu sach, thuat sach, thuoc sach
lu hanh » luu hanh, ly hanh, tu hanh
du hanh » dieu hanh, duy khanh, luu hanh
van hoc » van hoa
de hoc » te hoc, du hoc, dien hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( ((lu hanh) or (du hanh)) trinh thiet de hoc ) or ( thu sach trach nhiem van hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( ((lu hanh) OR (du hanh)) trinh thiet de hoc ) OR ( thu sach trach nhiem van hoc )).
• Adding a wildcard symbol may retrieve word variants: (( ((lu hanh) or (du hanh)) trinh thiet de hoc ) or ( thu sach trach nhiem van hoc ))*.