Perhaps you should try some spelling variations:
trach nhiem » trac nghiem
sach trach » sach tranh, sach truc, sat trach
tai nghiep » mai nghiep, trai nghiem, giai nghiep
tac nghiep » cac nghiep, trac nghiem, sach nghiep
thu sach » thuat sach, thuoc sach, thu hoach
nhiem va » nghiem va, hiem xa
vung moc » dung mo, dung moi, dung mot
tu sach » su sach, te sach, tu cach
va hoc » van hoc

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 trach nhiem va hoc ) or ( tu sach ((tai nghiep) OR (tac nghiep)) vung moc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( thu sach trach nhiem va hoc ) OR ( tu sach ((tai nghiep) OR (tac nghiep)) vung moc )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( thu sach trach nhiem va hoc ) or ( tu sach ((tai nghiep) OR (tac nghiep)) vung moc ))".
• Adding a wildcard symbol may retrieve word variants: (( thu sach trach nhiem va hoc ) or ( tu sach ((tai nghiep) OR (tac nghiep)) vung moc ))*.