The manuscript discusses a new procedure of designing a fractional order unknown input ob- server for nonlinear systems represented by fractional-order Takagi-Sugeno model with unmeasurable premise variables. While the topic might be of interest to specialized readers, it is not entirely clear why the new method has been proposed or whether the proposal assists an improvement from existing previous techniques. The following provides some remark to the manuscript. 1. I encourage the authors to transfer their typesetting into L A TEX. 2. The phrase ‘academic example’ is not clear. Are there non-academic examples? 3.References and citations for Riemann-Liouville, Grunwald-Letnikov and Caputo should be given and provided. 4. What are the similarities and the differences between the first and the second approaches? 5. Some paragraphs need to be reworded and rewritten again as they are not clear to the reader. Please obtain help in professional English. For instance, the are some French words inserted and the authors forgot to put period in many difference places at the end of a sentence or an equation. 6. The style of reference list is inconsistent, please fix this.

The authors have spent a great effort in converting the document into L A TEXand adding more refer- ences. However, some remarks from the first review are still ignored. 1. Before proving Theorem 1, the authors use Lemma 1. Lemma 1 is not stated but it is not proved. Is this too obvious for the readers or perhaps any reference available or perhaps a proof need to be provided. 2. Why the last sentence of the proof of Theorem 1 printed in italics? 3. Why the last two sentences of Theorem 2 mentioned Theorem 1? I guess that is a mistake. Please check and verify. 4. The word rank should not be written in italics. 5. The remark regarding using full stop and period has been ignored. Please fix this. 6. The authors have problem with using capitalization, dash sign and the use of -ly. Please fix this. 7. The reference list still has problem, particularly with spacing, the use of pages, pp, or directly page numbers. Please fix these. 8. The sentence on sample availability seems incomplete. Please complete this. 9. Please add more explanation in the figure caption. 10. Why four authors contribute equally to the work while one does not? Explain! 11. Please remove or complete the telephone information written after Affiliation 5. 12. The figure quality can be improved. The quality on the printed version is not that great. 13. Acknowledgment section is missing. 14. Overall, please obtain help in fixing the English professionally.

The reference list still has a problem with the spacing. Please fix this again. Otherwise, it seems everything is all right now.