Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
sach kho » bach khoa, sach dao, sach nha
tang mai » tang tai, lang mai, sang mai
tuan tai » toan tai, quan tai, tan tai
van tuan » van quan, van ban, anh tuan
luc van » luoc van, luu van, duc van
tang ma » mang may, tang van
ve cau » ke cau, ve cac, le cau
va cau » van cau, va cac, va dau
tai va » thai va, mai va, tri va
thiet » thieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc sach kho ((tang mai) or (tang ma)) hoi. hieu ((ve cau) or (va cau)) luc van tuan tai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach kho ((tang mai) OR (tang ma)) hoi. hieu ((ve cau) OR (va cau)) luc van tuan tai va thiet.
• Adding a wildcard symbol may retrieve word variants: thuoc sach kho ((tang mai) or (tang ma)) hoi. hieu ((ve cau) or (va cau)) luc van tuan tai va thiet*.