Perhaps you should try some spelling variations:
hoach quan » hoach quang, hoach luan, hoc quan
sach nang » sach dung, sach danh, sach song
toc sach » hoc sach, doc sach, thuoc sach
nang tai » hang tai, tang tai, sang tai
mang tri » lang tri, nang tri, quang tri
tu hoach » thu hoach, tu hach, quy hoach
tu cach » tu cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((( toc sach nang tai ) or ( tu cach mang tri ))) or ( tu hoach quan tri ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((( toc sach nang tai ) OR ( tu cach mang tri ))) OR ( tu hoach quan tri ))*.