Open Access Policy

To facilitate transition towards fully open access policy, Tsenov Publishing House, the principal owner of the copyright on all articles, published in this journal, imposes the following access policy:

/ All articles, published after 01 January 2019 are available under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Public License (CC BY-NC-ND 4.0). Full text of the license is available at the following link:

b/ All articles, published until 31 December 2018, shall be available under the following License Agreement.

Tsenov Publishing House

Special License Agreement for Journal Articles, Published Before 31 December 2018

By exercising the Licensed Rights (defined below), You accept and agree to be bound by the terms and conditions of this License Agreement. To the extent this License Agreement may be interpreted as a contract, You are granted the Licensed Rights in consideration of Your acceptance of these terms and conditions, and the Tsenov Publishing House (“Licensor”) grants You such rights in consideration of benefits the Licensor receives from making the Licensed Material available under these terms and conditions.


1. Licensed Material” will refer to all published articles (in print and in electronic form) in the journals of Tsenov Publishing House.
2.Full-text Access” shall mean any electronic or other means that allows the end user of the service/database/index to access the whole (or significant) content of a publication.


1. Patent and trademark rights are not licensed under this License Agreement.
2. For avoidance of any doubt, Tsenov Publishing House reserves the right to sublicense the Licensed Matherial under different conditions subject to other license agreements.

III.License conditions

1. Subject to the terms and conditions of this License Agreement, the Licensor hereby grants You a worldwide, royalty-free, non-sublicensable, non-exclusive, irrevocable license to exercise the Licensed Rights in the Licensed Material to:

      a/ access the Licensed Material located on the servers of the Licensor

      b/ make private copies of the Licensed Material for backup purposes only

      c/ make copies of the entire material or parts of it to be used in search indices, scientific databases, as long as the database/index does not provide end users with Full-text Access other than reference to the full text of the publication, located at the servers of the Tsenov Publishing House.

IV.Disclaimer of Warranties and Limitation of Liability.

1. Unless otherwise separately undertaken by the Licensor, to the extent possible, the Licensor offers the Licensed Material as-is and as-available, and makes no representations or warranties of any kind concerning the Licensed Material, whether express, implied, statutory, or other. This includes, without limitation, warranties of title, merchantability, fitness for a particular purpose, non-infringement, absence of latent or other defects, accuracy, or the presence or absence of errors, whether or not known or discoverable. Where disclaimers of warranties are not allowed in full or in part, this disclaimer may not apply to You.
2. To the extent possible, in no event will the Licensor be liable to You on any legal theory (including, without limitation, negligence) or otherwise for any direct, special, indirect, incidental, consequential, punitive, exemplary, or other losses, costs, expenses, or damages arising out of this License Agreement or use of the Licensed Material, even if the Licensor has been advised of the possibility of such losses, costs, expenses, or damages. Where a limitation of liability is not allowed in full or in part, this limitation may not apply to You.
3. The disclaimer of warranties and limitation of liability provided above shall be interpreted in a manner that, to the extent possible, most closely approximates an absolute disclaimer and waiver of all liability.

V.Term and Termination

1. This License Agreement applies for the term of the Copyright and Similar Rights licensed here. However, if You fail to comply with this License Agreement, then Your rights under this License Agreement terminate automatically.
2. Where Your right to use the Licensed Material has terminated, it reinstates upon express reinstatement by the Licensor.
3. For the avoidance of doubt, this section does not affect any right the Licensor may have to seek remedies for Your violations of this License Agreement.

VI.Other Terms and Conditions

1. The Licensor shall not be bound by any additional or different terms or conditions communicated by You unless expressly agreed.
2. Any arrangements, understandings, or agreements regarding the Licensed Material not stated herein are separate from and independent of the terms and conditions of this License Agreement.


1. For the avoidance of doubt, this License Agreement does not, and shall not be interpreted to, reduce, limit, restrict, or impose conditions on any use of the Licensed Material that could lawfully be made without permission under this License Agreement.
2. To the extent possible, if any provision of this License Agreement is deemed unenforceable, it shall be automatically reformed to the minimum extent necessary to make it enforceable. If the provision cannot be reformed, it shall be severed from this License Agreement without affecting the enforceability of the remaining terms and conditions.
3. No term or condition of this License Agreement will be waived and no failure to comply consented to unless expressly agreed to by the Licensor.
4. Nothing in this License Agreement constitutes or may be interpreted as a limitation upon, or waiver of, any privileges and immunities that apply to the Licensor or You, including from the legal processes of any jurisdiction or authority.