Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
sach thu » sach thue, sach thieu, sach tham
van hanh » van thanh, ban hanh, van anh
truc van » truc va, thuc van, truc ban
cam truc » cau truc, nam truc, lam truoc
hieu van » hieu va, thien van, lieu va
mang xa » mang may, dang xay, mang cua
van cam » van nam, van lam, van cau
lang xa » lang ha, dang xay, lang van
hanh ki » hanh vi, hanh ky, hanh kien
su viet » so viet
ki su » ky su

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 thu ((((lang xa) or (mang xa))) or (nang x)) hoi. hieu van cam truc van hanh ki su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach thu ((((lang xa) OR (mang xa))) OR (nang x)) hoi. hieu van cam truc van hanh ki su viet.
• Adding a wildcard symbol may retrieve word variants: thu sach thu ((((lang xa) or (mang xa))) or (nang x)) hoi. hieu van cam truc van hanh ki su viet*.