Perhaps you should try some spelling variations:
hanh khoi » hanh thoi, hang khoa, dang khoi
thuat dan » thuat san, thuat ban, thuat dam
mach khoa » bach khoa, anh khoa, may khoa
khoa khau » khoa kham, khoa phau, khoa chau
khau tong » khau thong, khau cong, khau thuong
sach thu » sach thue, sach thieu, sach tham
thu thuc » thuc thuc, thu thuoc, thue thuc
khoi han » hoi han, khoi can, khoa than
dan tren » dat tren, dau tren, van tren
tren vai » trien van, trang vai, tien va
vai mach » vi mach, ban mach, tao mach
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 thu thuc hanh khoi han tong ) or ( thuat dan tren vai mach khoa khau tong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach thu thuc hanh khoi han tong ) OR ( thuat dan tren vai mach khoa khau tong )).
• Adding a wildcard symbol may retrieve word variants: (( tu sach thu thuc hanh khoi han tong ) or ( thuat dan tren vai mach khoa khau tong ))*.