Perhaps you should try some spelling variations:
thuoc dang » thuoc dung, thuoc khang, thuc dan
thuc dang » thuc dan, thuc dung, thu dang
hanh tai » thanh tai, hang tai, han tai
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
su viet » so viet
tai su » tai so, tai tu, lai su
x hoi » xa hoi, o hoi, x ho
ha am » ha nam, ha lam, va am

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ky nang x hoi. hieu ((ha am) or (hoa am)) ((thuc dang) OR (thuoc dang)) hanh tai su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky nang x hoi. hieu ((ha am) OR (hoa am)) ((thuc dang) OR (thuoc dang)) hanh tai su viet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ky nang x hoi. hieu ((ha am) or (hoa am)) ((thuc dang) OR (thuoc dang)) hanh tai su viet*".