Perhaps you should try some spelling variations:
thi hang » thi hanh, thi nang, thi hong
hieu cac » hieu luc, hieu va, hieu van
cac chat » cao chat, cac thuat, cac nha
chat tai » chat thai, cao tai, khau tai
su triet » su viet, su tien, ve triet
tu sach » thu sach, su sach, te sach
va lanh » va lang, va hanh, va danh
tai va » thai va, mai va, tri va
dao su » dao suu, dan su, cao su

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ((thuc hanh) or (thi hang)) cau hoi. hieu cac chat tai va lanh dao su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((thuc hanh) OR (thi hang)) cau hoi. hieu cac chat tai va lanh dao su triet.
• Adding a wildcard symbol may retrieve word variants: tu sach ((thuc hanh) or (thi hang)) cau hoi. hieu cac chat tai va lanh dao su triet*.