Perhaps you should try some spelling variations:
sach tham » sach nha
tham thuc » nham thuc, pham thuc, tam thuc
thuc bach » truc bach, thuoc sach, thuc hanh
hanh thuc » nhanh thuc, hanh thuoc, hanh phuc
thuc thuc » hoc thuc
thuc cach » thuoc sach, truoc cach, thuc hanh
cach thoi » cac thoi, cach thuc, cach noi
khe khong » khoi khong, khon khong, nghe khong
bach hoa » bach khoa, bach ha, cach hoan
he khong » he thong
thoi khe » thoi khac, thoi ky, thoi ki
tu sach » thu sach, su sach, te sach
tu hanh » du hanh, lu hanh, thuc hanh

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 tham thuc bach hoa he khong ) or ( tu hanh thuc thuc cach thoi khe khong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach tham thuc bach hoa he khong ) OR ( tu hanh thuc thuc cach thoi khe khong )).
• Adding a wildcard symbol may retrieve word variants: (( tu sach tham thuc bach hoa he khong ) or ( tu hanh thuc thuc cach thoi khe khong ))*.