Perhaps you should try some spelling variations:
hoach chinh » hanh chinh, hoan chinh, hoc chinh
sach tranh » canh tranh
sach trinh » hanh trinh, sach kinh, sach tren
sach danh » sach dao, sach dung, sach kinh
trinh tai » trinh toan, trinh tu, trinh han
tu hoach » thu hoach, tu hach, quy hoach
tu sach » thu sach, su sach, te sach

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 danh) or (sach tranh)) tri ) or ( tu hoach chinh tri ))) or ( tu sach trinh tai ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((( tu ((sach danh) OR (sach tranh)) tri ) OR ( tu hoach chinh tri ))) OR ( tu sach trinh tai )).
• Adding a wildcard symbol may retrieve word variants: (((( tu ((sach danh) or (sach tranh)) tri ) or ( tu hoach chinh tri ))) or ( tu sach trinh tai ))*.