Perhaps you should try some spelling variations:
sach thue » sach thieu, sach tham, cach thuc
dang van » hoang van, hang va
tang tai » hang tai, dung tai, sang tao
tai khoa » da khoa, noi khoa
sach thu » sach thieu, sach tham, cach thuc
duc van » duc va, duc tan, duc manh
van cua » vang cua, ban cua, dan cua
xuc van » luc van, vuc van, xuc ban
hieu va » lieu va, hieu qua
va cam » va cham, va cac, va cao
cua tu » cua tuc, cua su, cua cu

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 thu) OR (sach thue)) tang tai khoa. hieu va cam ((xuc van) or (duc van)) dang van cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach thu) OR (sach thue)) tang tai khoa. hieu va cam ((xuc van) OR (duc van)) dang van cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach thu) OR (sach thue)) tang tai khoa. hieu va cam ((xuc van) or (duc van)) dang van cua tu".
• Adding a wildcard symbol may retrieve word variants: te ((sach thu) OR (sach thue)) tang tai khoa. hieu va cam ((xuc van) or (duc van)) dang van cua tu*.