Perhaps you should try some spelling variations:
thieu quang » hieu quang, thien quan, trien quang
trong than » trong thanh, trong thuan, trong tan
hoc thieu » toc thieu, hoc hien
chinh tan » chinh tai, chinh ta, chinh ban
tan dung » tran dung, tin dung, van dung
than hoc » toan hoc, thai hoc, than doc

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc thieu quang - hanh chinh tan dung trong than hoc cao~.
• Adding a wildcard symbol may retrieve word variants: hoc thieu quang - hanh chinh tan dung trong than hoc cao*.